Synonym of on one's mettle

resolute intent resolved committed dedicated determined steadfast dogged earnest firm intransigent obdurate obstinate purposeful relentless set stalwart tenacious uncompromising unswerving unwavering constant indefatigable mettlesome perseverant persevering persistent pertinacious spirited staunch steely strong stubborn undaunted unflinching unrelenting faithful gritty immovable implacable indomitable inflexible intrepid plucky true unbending unshakeable unshaken valiant vigorous adamant bold bound brave courageous decided decisive fixed gutsy indurate insistent purposive steady unfaltering unflagging unhesitating unshakable unyielding definite deliberate immutable loyal manful persisting serious spunky stiff stout strenuous unbendable unchanging bulldog out peremptory settled single-minded strong-minded strong-willed do-or-die four-square intent on stout-hearted bent on rock-ribbed set on bent upon dead set on insistent on intent upon meaning business determined to hell bent on hell-bent on hell-bent upon committed to the idea of tall in the saddle no-nonsense tough untiring zealous ardent devoted forceful inexorable hard tireless driven rigid fearless hardened lionhearted doughty daring heroic keen wilful enduring willful assertive dauntless intense hard-nosed bullheaded energetic enthusiastic sure assiduous devout hardy undeviating active valorous eager headstrong solid feisty gallant rigorous mulish reliable diligent audacious fanatical intractable unremitting unfailing game ballsy wholehearted iron-willed industrious true-blue enterprising dependable emphatic pigheaded stiff-necked strict adamantine stable sturdy passionate stouthearted aggressive adventurous self-willed dead set trusty confident hardheaded bent hard-line vehement dyed-in-the-wool unafraid fervent dutiful focused fast nervy ossified perverse diehard fierce pat gutty resilient heroical trustworthy opinionated genuine dashing undauntable sedulous focussed inconvincible pious greathearted grim ruthless unchangeable avid full of determination unqualified stringent lion-hearted good motivated unmalleable certain conscientious dynamic self-opinionated sincere hardline allegiant ambitious abiding pushy powerful deep-dyed rugged patient venturous hard-working inveterate concentrated cast-iron obsessed sound stanch deep robust positive fervid die-hard importunate down-the-line hell-bent venturesome hardcore severe assured unshrinking absolute harsh daredevil unvarying secure intensive bound and determined obsessive unadaptable stern durable incessant inexhaustible unwearied self-assertive set in stone never-failing hard-core weariless established unmovable uncooperative refractory unflappable iron adventuresome unappeasable responsible unalterable thorough all-out straight exacting fiery honest consistent go-getting locked in have-a-go high-spirited bloody-minded draconian confirmed unswayable ironclad demanding permanent invariable dour complete tried and true tried and tested entrenched unpersuadable hard and fast unvacillating sworn unsentimental scrupulous hard-driving domineering impassioned unquestioning deep-rooted compulsive self-starting honourable honorable fixated goal-oriented unceasing tried thoroughgoing aspiring bull-headed militant self-driven unswervable changeless inured merciless authoritarian tried-and-true concerted total regular Herculean perpetual self-confident supportive unabashed nerved toughened true blue manly unconditional grind hyper emboldened unwearying rooted unfearful long-standing close impervious long-lasting deep-seated hearty patriotic bred-in-the-bone card-carrying inspired intrenched hungry heavy-handed upright desirous true-hearted pure striving resounding thirsty hanging tough violent unsparing explicit unalarmed perdurable sustained painstaking unrestrained iron-fisted resistant redoubtable out-and-out calculable trustable attached brick-wall safe swashbuckling unforgiving rash through and through lasting well-built temerarious brash extreme austere recalcitrant lusty tough-minded full-blooded engrossed forcible indelible tough nut free-swinging potent trusted commanding hard as nails in-your-face eternal muscular seasoned red-hot ingrained jumping perky attentive as game as Ned Kelly monomaniacal fire-eating continuous high-powered truthful unfluctuating formidable adherent categorical perennial on the go ball of fire unapologetic unashamed stubborn as a mule incorruptible lifelong indestructible irrepressible radical ineradicable continuing ferocious fair pressing pledged torrid wild profound uncompliant uniform imperious pitiless unaccommodating supreme desperate studious invariant in earnest unchanged reckless static chivalrous dominant incurable eager beaver meticulous fundamentalist orthodox liege mad keen hard-hitting unblenching foolhardy all out undismayed spartan out and out hard-and-fast self-assured reverent self-possessed two-fisted set in one's ways clamorous invincible hard-bitten aweless flat-out unsympathetic stand pat well-made noble unreserved standing one's ground careful detailed contrary hang tough entreating direct go-ahead built to last worthy strongly made full unquestioned searching religious undoubting unstoppable absorbed exigent consumed compelled well-founded downright methodical independent balky renitent outright chronic habitual possessed bullish preoccupied furious urgent gung ho concentrating immersed hidebound unstinted undeterred sagacious authoritative galvanized impelled occupied oppressive ethical righteous laborious blunt burning determinate frozen irreversible revering uncontrolled unbridled unabated concrete moral virtuous decent perfervid veracious bossy induced obsessional disciplinary categoric stony imperishable unending venerating cruel proved incorrigible stark utter punchy never-tiring lively inexpugnable unmitigated substantial pushed steered guided impulsive besetting galvanised sheer inalterable infallible impenitent irredeemable unreformable longtime clean consummate arrant through-and-through unpermissive bulletproof unmoved clamant obedient plumb simple rank stone not giving an inch unalloyed unadulterated affectionate accustomed habituated staid bombproof unmistakable flat cotton-picking very perfect brisk progressive pioneering even red-blooded brassbound mean business deadly dead dreadful can-do peppery gingery sicker unfearing hopeful crashing bodacious blooming competitive dug in incompliant drastic unmodified standing pat on the level conclusive blank long-established behind one wrapped up resolved to stony-hearted pig-headed thick-skinned callous sticking to one's guns single-minded about firm about heavy-duty bona fide ramrod cool dire impavid full-on urged on self-asserting rough death-or-glory pulling no punches well-constructed self-seeking get up and go power-hungry high-reaching obsessive about well established inflexible about stop at nothing fixated on serious-minded fanatical about hard-hearted hard-wearing truehearted deep-set hard-shell made to last power-loving all-consuming puissant firmly established on task straight-out well-established unassailable self-disciplined hardboiled buckled down uncomplaining long-suffering realistic firmly-based restless irremovable repeated not joking bolshie bravehearted steely-eyed ornery restive sporting ever-enduring unblinking immoveable unconquerable ever-abiding unintimidated awkward cocksure untameable cantankerous mullish hellbent uninfluenced cussed unsinkable impregnable perseverative unretiring contumacious unstinting pounding forbidding illiberal remorseless cohesive froward unsurpassable invulnerable great possessive blinkered whole-hearted manic traditional conservative uptight picky resolute about cross-grained unbudgeable true to life iron-jawed comprehensive prayerful vital regimented sticky hardworking balanced prevailing mighty brassy frightless exhaustive full-scale impassive going engagé unimpressionable equable disciplined controlled foolproof puritanical fit undiscouraged self-motivated calculated maximum hard-headed perceptive mean take charge tight undefeatable effective tested narrow-minded unquenchable bitter granite imposing confining binding unpliable locked cynical stuffy businesslike cutthroat orped capable dogmatic unflexible crisp doctrinaire forward controlling driving firm in spirit animated resourceful riveted long-lived in for long haul bloodthirsty tiger unlimited optimum in place in position not afraid overbearing on one's side insistent about bantam assuming macho thrusting observant defiant warlike gladiatorial brutal scrappy well balanced well-balanced exact pushing playing hard ball pushful set in concrete keen as mustard set in your ways going for broke self-learning be out for blood nose to the grindstone engaged enthralled sensible heartfelt meaning what one says collected composed like bad penny grave clear-sighted straight out single-hearted old faithful flinty confiding loving circumspect string along with entire all exclusive enrapt whole undivided herolike frisky sprightly mettled impressive titanic not backward in coming forward take-charge principled credible unmoving not put off not discouraged as keen as mustard true to the end given over to error-tolerant everlasting poised never give up unplacatable unmollifiable unpacifiable unconcerned unworried unapprehensive imperative crying reiterative monotonous unvaried cut-throat necessary do or die hold the fort hold your ground hold the line humble level-headed authentic on board watchful alert Ramboesque difficult to keep down impatient full-blown full-frontal pleading unaltered tough as old boots disciplinarian ascetical by the book hardhearted astringent uncharitable tyrannical browbeating ascetic autocratic as thick as thieves boon inseparable bosom tough nut to crack decided upon writ in stone cut-and-dried strait-laced cold impartial unfeigned uncontrived equitable unpretentious reputable cocky undisturbed icy carefree intensely competitive fiercely competitive having killer instinct dog-eat-dog hang-tough high-pressure go for broke iron-handed rolling with punches quick to recover quick to bounce back feverish daunting like a ball of fire on the make career-minded desiring success in the bag shoo-in sanguine nailed down able locked on closely controlled strictly controlled rigidly enforced endless right just nice uncaring adoring doting rabid fond big exuberant beseeching begging unaffected as tough as old boots right-minded timeless superheated elaborate self-reliant pugnacious go-go massed impermeable remove procrustean concerned with veridical no lie undistorted up front square creditable all right on the up and up estimable high-principled stationary awesome tremendous cool-headed solidified husky taut hard-shelled hard-boiled uninterrupted persuasive indefinite explosive charged heated warm volatile emotional demonstrative warm-blooded ungovernable hot-blooded extensive sealed blocked standing unbothered untouched sweeping never-ending awe-inspiring compact dimensional consolidated minding incandescent passional minute on an even keel compacted rocklike impliable widespread quality thick congealed serviceable out to fixed upon anxious to committed to intending to fixed on obsessed with resolved on impatient to decisive about determined on turbulent incommutable stiffened dense jellied impenetrable brick wall rock-solid rock-hard non-flexible unfading plain like a rock unmodifiable final really hard very hard inevitable unequivocal madcap arduous taxing exhausting overbold overconfident unquestionable risky to the core deep-down full-fledged right-down ungoverned temeritous uncurbed indubitable unrestricted devil-may-care death-defying point blank point-blank

on one's mind on one's mother's side on one's own on one's own hook on one's own initiative on one's own time on one's lonesome on one's knees on one's Jack Jones on one's jack on one side on one's heels