Other forms: assumptions
An assumption is something you treat as true without checking it. You booked the restaurant on the assumption that everybody eats fish; the whole plan rests on the assumption that the roads will be clear on a Sunday.
It comes in a fixed frame: make an assumption, work on the assumption that, a safe assumption, an underlying assumption, and the standard warning about what assumptions do to you. In logic it is the same thing said strictly — a starting point accepted without argument, so a conclusion is only ever as strong as the assumption beneath it. A second, quite separate sense turns up in formal writing: the assumption of power, the assumption of responsibility, meaning the taking on of it. Keep the verbs straight — you assume something, and then you have made an assumption.
1nounassumptionSomething accepted as true without proof or checking.~67%
“Their assumption that he could drive turned out to be wrong.”
synonyms: presumption, supposition, premise
2nounactThe act of taking on a duty, role or power.~33%
“His assumption of the chairmanship surprised the whole committee.”
Shares are an estimate: a language model read 6 sentences found in the wild and placed 6 of them on a sense — a count of our sample, not a measurement of English.
assumption is an unproved starting point.
Assumption came through Middle English assumpcioun from Latin assūmptiō, 'a taking up, adoption', and from Medieval Latin, where it meant a taking up into heaven — which is why the Assumption with a capital A is a feast day. The logical sense was already there in Latin: assūmptiō named the minor proposition of a syllogism, the thing you pick up and use in an argument.
Latin
assūmptiō
Middle English
assumpcioun
English, today
assumption
From Middle English assumpcioun, from Latin assūmptiō. From Middle English assumpcioun, from Medieval Latin assūmptiō (“a taking up (into heaven)”) and Latin assūmptiō (“a taking up, adoption, the minor proposition of a syllogism”) (whence -ion), from Latin assūmō (whence as-. See also assume. a doublet of assumptio.
Etymology from Wiktionary, CC BY-SA