All foolproof synonyms
fool·proof
F f adj foolproof
- infallible — absolutely trustworthy or sure: an infallible rule.
- flawless — having no defects or faults, especially none that diminish the value of something: a flawless Ming Dynasty vase.
- reliable — that may be relied on or trusted; dependable in achievement, accuracy, honesty, etc.: reliable information.
- sure-fire — sure to work; foolproof: a surefire moneymaking scheme.
- unassailable — not open to attack or assault, as by military force or argument: unassailable fortifications; unassailable logic.
- perfect — conforming absolutely to the description or definition of an ideal type: a perfect sphere; a perfect gentleman.
- tested — the means by which the presence, quality, or genuineness of anything is determined; a means of trial.
- tried — simple past tense and past participle of try.
- guaranteed — a promise or assurance, especially one in writing, that something is of specified quality, content, benefit, etc., or that it will perform satisfactorily for a given length of time: a money-back guarantee.
- certain — If you are certain about something, you firmly believe it is true and have no doubt about it. If you are not certain about something, you do not have definite knowledge about it.
- dependable — If you say that someone or something is dependable, you approve of them because you feel that you can be sure that they will always act consistently or sensibly, or do what you need them to do.
- fail-safe — Electronics. pertaining to or noting a mechanism built into a system, as in an early warning system or a nuclear reactor, for insuring safety should the system fail to operate properly.
- faultless — without fault, flaw, or defect; perfect.
- safe — secure from liability to harm, injury, danger, or risk: a safe place.
- sure — free from doubt as to the reliability, character, action, etc., of something: to be sure of one's data.
- unerring — not erring; not going astray or missing the mark: The captain set an unerring course for home.
- unfailing — not failing; not giving way; not falling short of expectation; completely dependable: an unfailing friend.
- idiot-proof — built, organized, written, etc., in such a way as to be usable by or understandable to any person of average intelligence or skill: an idiot-proof camera.
adjective foolproof
- secure — free from or not exposed to danger or harm; safe.