Believable means sounding true enough to be accepted. A believable story, hardly believable, a believable character.
In fiction it is the standard praise for a character who behaves consistently, and it is a different thing from realistic. Believable and credible mean the same, with credible sounding more formal. Neither says the thing is actually true.
1adjectivebelievableSounding true enough to be accepted.
“The actor made the character so believable that you forgot he was acting.”
believable is a quality.
Believe plus -able, from Old English geliefan, to hold dear or trust.
Middle English
bilevable
English, today
believable
From Middle English bilevable. From Middle English bilevable, beleevable, equivalent to believe + able.
Etymology from Wiktionary, CC BY-SA