foolproof
[adjective]
Synonyms: infallible, certain, guaranteed, safe, sure-fire (informal), unassailable, unbreakable

[TahlilGaran] English Synonym Dictionary ▲

fool‧proof /ˈfuːlpruːf/ adjective
a foolproof method, plan, system etc is certain to be successful Synonym : infallible:
a foolproof way of preventing credit card fraud

[TahlilGaran] Dictionary of Contemporary English ▲

foolproof
adj.
VERBS be, look, seem | make sth We're trying to work out a way to make the system foolproof.
ADV. absolutely, quite | nearly, pretty well, virtually The system is pretty well foolproof.

[TahlilGaran] Collocations Dictionary ▲

foolproof
adj. So constructed that not even a fool can spoil it; easy.
This entrance examination is so easy that it is actually foolproof.

[TahlilGaran] English Idioms Dictionary ▲