In fae lih bəl
adjective
1. incapable of error.
The computer’s calculation is considered infallible.
You are wrong if you think you’re infallible; you’re bound to make a mistake one day that you’ll seriously regret.
2. not liable to error or failure; extremely reliable.
I will rely on your infallible judgment.
The book is an infallible guide to travel in Italy.
3. of the pope, incapable of fallacy or error in expounding Roman Catholic doctrine on faith or morals.
