Certeinte

Part of speech: noun

Definitions

1. Firm knowledge or confidence that something is true, an archaic Middle English form of certainty
2. The state of being fully assured that a matter is settled, as the word was spelled in medieval English
3. Unshakable confidence in the truth of a fact, a medieval spelling of the modern word for sureness

Etymology: "Certeinte" is the Middle English spelling of what is now "certainty." It came into English from Old French "certeinté," formed by adding the suffix "-té" (the source of modern "-ty") to "certain." The surprise lies further back. "Certain" comes from Latin "certus," meaning "decided" or "settled," the past participle of "cernere," "to separate, sift, or determine." That same root lies behind "discern," which began as a word for sifting things apart, and "decree," a formal decision. A certainty was therefore, at root, something that had been sifted out and settled.