notion

idea, concept, conception, thought, notion, impression mean what exists in the mind as a representation (as of something comprehended) or as a formulation (as of a plan). idea may apply to a mental image or formulation of something seen or known or imagined, to a pure abstraction, or to something assumed or vaguely sensed.

• • innovative ideas
• • my idea of paradise

concept may apply to the idea formed by consideration of instances of a species or genus or, more broadly, to any idea of what a thing ought to be.

• • a society with no concept of private property

conception is often interchangeable with concept; it may stress the process of imagining or formulating rather than the result.

• • our changing conception of what constitutes art

thought is likely to suggest the result of reflecting, reasoning, or meditating rather than of imagining.

• • commit your thoughts to paper

notion suggests an idea not much resolved by analysis or reflection and may suggest the capricious or accidental.

• • you have the oddest notions

impression applies to an idea or notion resulting immediately from some stimulation of the senses.

• • the first impression is of soaring height