presume

Presume is a verb meaning to suppose something is true based on probability, reasoning, or reasonable grounds, without certain proof. It can also mean to undertake or assume something on the basis of what is believed. The word carries a sense of justification or legitimacy beyond a mere guess. The related noun is presumption, and the adjective form is presumed.

Etymology traces presume to the Latin praesumere, meaning “take beforehand” (prae- “before” + sumere “take up”). In common usage, presume often conveys a reasonable or warranted assumption, while in formal contexts it can imply a statutory or established default.

Usage and nuances: In everyday speech, one may say, “We presume he will arrive on time,” or “I presume you’re finished.” In legal contexts, a presumption is a rule of law or a assumption of fact that remains until contradicted by evidence, such as the presumption of innocence: “The defendant is presumed innocent until proven guilty.” The phrase “presume upon” or “presume on” can indicate taking unfair advantage of someone’s generosity or hospitality, as in “Do not presume upon my hospitality.”

Differences from assume: Although often used interchangeably, presume tends to imply a basis in evidence, authority, or probability, whereas assume can suggest taking on a role or forming a belief without strong justification. Both terms are common in formal and informal writing, with presumption often signaling a more established or legally recognized stance.