Pronunciation: (bi-lēf'),[key] —n. 1. something believed; an opinion or conviction: a belief that the earth is flat. 2. confidence in the truth or existence of something not immediately susceptible to rigorous proof: a statement unworthy of belief. 3. confidence; faith; trust: a child's belief in his parents. 4. a religious tenet or tenets; religious creed or faith: the Christian belief.