How to say "notion" in Japanese

• コンセプトCommon
  nounA katakana loanword for the guiding idea or underlying concept behind a design, product, or plan; 'notion' here means a deliberate, shaping idea rather than a passing personal thought.
  エメットのコンセプトをもっともよく表現ひょうげんしているデザインに特とくに焦点しょうてんを当あてたい。↗

  I would like to focus attention on the particular design that best represents Emmet's concept.
• 概念がいねんJLPT N1approx.Common
  nounCovers 'notion' in its most abstract sense: a general idea or concept formed in the mind, the kind discussed in philosophy, science, and academic writing. For this sense it is the usual choice.
  彼かれの福祉ふくしの概念がいねんはかなり観念的かんねんてきだ。↗

  His notion of welfare is pretty abstract.
• 観念かんねんJLPT N2approx.Common
  nounAn idea or notion as something held in the mind, often with a psychological coloring — a conception one carries, sometimes a preconception. For a neutral abstract notion, 概念 is generally the better pick.
  幸福こうふくの観念かんねんはきわめて抽象的ちゅうしょうてきだ。↗

  The idea of happiness is extremely abstract.
• 命題めいだいCommon
  no-adjectiveReally 'proposition': a statement or thesis in logic, mathematics, or debate. Its 'notion' gloss belongs to that technical frame, so it is seldom the word you want for an everyday notion.
• 考えかんがえJLPT N3approx.Common
  nounUse this for 'notion' meaning a person's idea, view, or opinion — what someone thinks about something. It is the natural choice when 'notion' refers to an individual's thinking rather than an abstract concept.

Use 概念 for an abstract general notion, 「コンセプト」 for the guiding idea behind a design or plan, 「考え」 for a person's idea or view, 観念 for an idea held in the mind, and 命題 only for a logical proposition.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• コンセプトconcept
• 概念がいねんgeneral idea
• 観念かんねんidea
• 命題めいだいproposition
• 考えかんがえidea