adj.
- Incapable of erring: an infallible guide; an infallible source of information.
- Incapable of failing; certain: an infallible antidote; an infallible rule.
- Roman Catholic Church. Incapable of error in expounding doctrine on faith or morals.
[Middle English, from Medieval Latin īnfallibilis : Latin in-, not; see in-1 + Medieval Latin fallibilis, fallible; see fallible.]
infallibility in·fal'li·bil'i·ty or in·fal'li·ble·ness n.infallibly in·fal'li·bly adv.
The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.
