Believe and similar words

STUDY
PLAY
Believe
Verb: to have faith or confidence; to accept as a true or real; to expect
belief
Noun: the mental act of placing confidence or trust in another
believable
Adjective: capable of eliciting belief or trust
unbelievable
Adjective: not to be believed, incredible; astonishing, extraordinary
believably
Adverb: in a believable manner; credibly, plausibly