Certainty

Part of speech: noun

Pronunciation: /ˈsɝtn̩ti/

Definitions

1. The condition of being completely confident or sure about something
2. The quality of having no doubt and being fully convinced in one's belief or knowledge
3. A firm conviction or assurance that something is true or will happen

Etymology: Certainty traces back to a Latin adjective, "certus," meaning "settled" or "determined," the same root that gives English "certain" and "certify." The noun was built from it in Latin's later, spoken phase: a form like "certānitās" appears in Vulgar Latin, the everyday speech that evolved into the Romance languages, and it passed into Old French as "certeinete." From there it entered Anglo-Norman and then Middle English as "certeynte," and at that stage it meant "surety," a guarantee or pledge that something would happen. The shift from guarantee to inner conviction is the notable part. The word began as something you could hold in the world, an assurance someone gave you, and gradually came to describe the mental state of being sure. Modern "certainty" keeps both senses in play: we can speak of the certainty of a result, or of our own certainty about it.

Synonyms: confidence, assurance, conviction, surety, definiteness

Antonyms: uncertainty, doubt, ambiguity