n.1 a a person's religion; religious conviction (has no belief). b a firm opinion (my belief is that he did it). c an acceptance (of a thing, fact, statement, etc.) (belief in the afterlife).
2 (usu. foll. by in) trust or confidence.
Phrases and idioms:
beyond belief incredible. to the best of my belief in my genuine opinion.
Etymology: ME f. OE geleafa (as BELIEVE)