unbelief Get Printable Handwriting (un-be-lief) 3 syllables Learn It! Spelling Test Definition noun. a withholding or lack of belief; esp. in religion or in certain religious doctrines Example Sentence Her unbelief in Santa Claus caused a disruption in class. Synonyms doubt; disbelief; distrust; dubiety; incredulity Antonyms belief Share with your friends: