DictionarynotionIdea or belief
noun

notion

NOH-shuhn/ˈnəʊʃn/

An idea or belief about something.

The woman's rough sketch expresses her notion of bridging the channel with a plank.

A tentative idea made visible: a woman beside a small garden drainage channel holds up a rough pictorial proposal for a simple plank crossing.
Etymology

Latin notio named a concept or idea and was formed from a verb meaning “come to know.” English extended this mental-conception sense to an opinion or a somewhat vague belief.

In context

U.S. Naval War College38:25
it's this notion if you put a guard in a guard Tower and and tint the windows the inmates have to assume they're being watched all of the time and it exerts control over them
NWC Issues in National Security Lecture Series, Lecture 6 "Humans v. Machines"

More examples

  • I have only a vague notion of how this works.
  • His notions about healthy eating change with every new study.
  • The book challenges our notion of what makes a family.

Forms

notion · notions

notional adjective — Existing as an idea rather than reality.

Similar words

idea
A broader term that also includes plans and suggestions.
belief
Suggests stronger acceptance that something is true or real.
impression
Emphasizes an understanding formed through limited observation or experience.