Synonym of fail safe

sure infallible certain unfailing surefire can't-miss definite assured constant reliable dependable endless boundless never-failing inexhaustible steadfast continuous ceaseless faithful undying unerring persistent loyal true continual steady unlimited unfading bottomless unflagging staunch come-through abiding unshakable tried-and-true delivering solid enduring invariable continuing lasting diligent same unrelenting unchanging consistent straight eternal assiduous absolute there dyed-in-the-wool trustworthy tried and true counted on tried and tested rock solid

confident covered dependable foolproof goofproof guaranteed protected reliable reliant safeguarded secure sound safe infallible sure certain sure-fire trustworthy unfailing tried and true tried and tested efficacious effective unerring never-failing can't-miss surefire good tested watertight never failing failsafe faultless accurate correct authoritative unquestionable exact unimpeachable assured excellent perfect flawless unassailable tried unbreakable idiot-proof airtight sovereign decided stipulated stated insured concluded warranted certified ensured well-built well-engineered well engineered high-quality credible irrefutable errorless believable convincing definitive without error true on the money kosher valid precise veracious thorough authentic all right unbeatable acceptable omniscient handy apodictic incontrovertible satisfactory helpful solid agreeable undeceivable always effective useful effectual inerrant steady inerrable efficient satisfying positive right staunch honourable trusty responsible reputable faithful honest virtuous sensible ethical incorruptible principled upright steadfast truthful loyal unswerving unwavering constant calculable righteous mature trustable honorable straight saintly fly right worthy of trust to be trusted above suspicion level-headed true blue boy scout tried and trusted up front down home tried-and-true on the level straight-up true-blue full of integrity rock solid always there as good as one's word

tried reliable dependable sure true trustworthy certain trusted unfailing attested calculable established good proved proven responsible safe secure solid sound steady tested trustable trusty approved certified classic consistent constant demonstrated failsafe faithful recognised recognized reputable staunch steadfast used tried and tested tried and true tried-and-true time-honoured tried out true-blue put to the test safe as houses demonstrable foolproof well engineered tested and proved well-built time-tested high-quality well-founded well-engineered well-tried well-grounded

guaranteed certain sure definite affirmed sealed cast-iron sure-fire a lock in the bag on ice for sure sure enough for a fact assured firm confirmed unimpeachable certified established watertight unshakable settled fixed secured bound attested copper-bottomed iron-clad nailed-on categorical unfailing infallible conclusive undeniable irrefutable unambiguous inevitable unequivocal clear absolute indisputable decisive incontrovertible unerring authoritative true concrete unmistakable indubitable genuine palpable irrevocable foolproof recognized confirmable real resolute unquestionable patent doubtless verifiable manifest surefire obvious secure determinate incontestable demonstrable positive undoubted accurate unqualified solid convincing questionless safe transparent recognised inerrant precise failsafe can't-miss as sure as eggs is eggs

safeguard precaution preventive palladium caution protection security defence shield defense insurance preventive measure deterrent provision guard prophylactic screen buffer safety measure safety device safety net protector safety valve fallback protective umbrella sheet anchor safety plug hindrance block preventative impediment prevention remedy protective obstruction curb obstacle check restraint precautionary measure neutralizer forethought prudence care anticipation disincentive protective measure backstop circumspection foresight wariness providence canniness discretion discreetness regard preventative measure anticipatory measure belt and braces cover aegis surety armor shelter ward buckler ammunition egis wall indemnity armour bulwark escort armament convoy safety cushion support immunity barrier fortification safeguarding guarding preservation assurance stronghold safekeeping refuge shielding guarantee bastion bumper guardianship resistance sanctuary custody hedge conservation indemnification salvation pad buttress rampart supporter defender warranty keeping fence coverage shock absorber mainstay prop trust weapon haven fender deterrence safeness charge maintenance protecting asylum upkeep upholding barricade custodianship backing reassurance fastness keep supervision mail saving warrant tutelage safe keeping resilience insurance policy cocoon cushioning invulnerability shade strength surveillance certainty protective device safety guard insurance cover absorber stability allowance endorsement self-defense good hands warfare weaponry munitions something to fall back on defenses defences apron mask financial protection hiding concealment housing citadel arms harbour retreat harbor life assurance life insurance preventative medicine preventive medicine preserving conserving sustentation harborage perpetuation safe harbor preserval evaporation care and feeding storage tanning refrigeration hiding place reinforcement plate breastplate panoply possession armor plate suit of armor protective clothing bulletproof vest chain mail flak jacket coat of mail suit of armour body armor body armour breastwork embankment bank castellation battlements pledge protectorship patronage trusteeship battlement bartizan earthwork collateral partition protective wall parapet buffet pawn bond underwriting gage hostage earnest guaranty bail covenant gauge contract

safety valve overflow safety device safety precaution valve insurance shield guard screen protection safety net preventive measure safety plug sheet anchor buffer fallback protective umbrella safeguard bulwark cover armor buckler ward ammunition wall aegis egis armour armament bumper pad rampart cushion fender fence protective device safety safety guard security defence precaution preventive surety prophylactic palladium provision shelter defense caution indemnity escort convoy safety measure

fail-safes fails at fails heavily fails miserably fails to fails to agree failsafe fails failproof failovers failover fail miserably