Believability

Part of speech: noun

Definitions

1. The quality of being worthy of trust or acceptance as true, or the capacity to convince someone that something is genuine or credible
2. The attribute of being reliable or plausible, which allows ideas or statements to be regarded as true or credible in the eyes of others
3. The characteristic that determines how convincingly something can be accepted as true or plausible, affecting its trustworthiness

Etymology: "Believability" is a plain formation: the verb "believe" with the suffix "-ability," which turns an adjective ending in "-able" into a noun meaning the quality of being that thing. Here the adjective "believable" is itself built from "believe" plus "-able," so the word is one step further along the same path. The suffix ultimately traces back through Latin "-abilitas," which in turn descends from "-ābilis," a form meaning capable of being done or having a certain quality. The verb underneath is the more interesting part. English "believe" comes from Old English "belīefan," a compound of the prefix "be-" and the verb "lȳfan," meaning to allow, permit, or give. Its older sense was closer to "hold dear" or "to hold as true" than to the modern idea of mental assent, which is why the root word carries a sense of trust and commitment. Middle English "bileven" passed this along to the modern verb.

Synonyms: credibility, plausibility, trustworthiness

Antonyms: implausibility, incredibility