Synonyms for foolproof

Most common

bullet-proof · infallible · failproof

All synonyms

Adjective

Definitions

1. adj. 1

   Of a device: protected against, or designed to be proof against, misuse or error.

Example sentences

• infallible The justice system is not infallible; mistakes happen.

Popularity over time

Use in printed books, per decade from 1850 to 2019.

By length

9 letters

unfailing³, failproof

10 letters

infallible⁴

The small number after each word is its number of syllables (unfailing³ = 3 syllables).