Definition
A belief, idea, or understanding about something, often one that is general or not fully formed.
Example
She had no notion of how hard the job would be.
Show translation
She had no idea how hard the job would be.
Etymology
From Latin *notio* ("a becoming acquainted with, an idea"), derived from *noscere* ("to know"). Entered English via Old French in the late 14th century. Related to *notice*, *notify*, and *notorious* — all sharing the Latin root of knowing or making known.
Cultural note
In American English, *notion* can carry a slightly whimsical or tentative flavor — saying "I had a notion to call him" suggests an impulse rather than a firm plan. In older Southern U.S. speech this use is especially vivid. Be careful not to confuse it with *notion* in the retail sense (a small sewing accessory like a button or thread), which is a distinct and now somewhat dated meaning found mainly in haberdashery contexts.