The Open Dictionary

idea

noun

UK/aɪˈdɪə/
US/aɪˈdiː.ə/

Definitions of idea noun

suggestion

  1. A2Countable

    a suggestion or plan for doing something

    • I have an idea—how about we head to the beach?

    • "Let's go for a walk in the park." "That's a great idea!"

    • Let me know if you have any thoughts about what I could buy for Jack.

thought

  1. B2UncountableSingular

    an understanding, thought, or picture in your mind

    • Do you have any idea what he looks like?

    • Can you give me an idea of the approximate cost?

    • I dislike the notion of living so far from home.

belief

  1. B1Countable

    a belief or opinion

    • We hold vastly different opinions regarding how to discipline children.

    • Dr. Leach's view is that it is not possible to spoil a child.

    • I'm not married; where did you get that impression?

purpose

  1. C1Singular

    a purpose or reason for doing something

    • The purpose of the game is to get rid of all your cards as quickly as possible.

    • The sole purpose of advertising is to persuade people to buy products.

    • The intent behind the lottery is to raise funds for charitable causes.

Phrases of idea noun

  • have no idea

    To be completely unaware of or uninformed about something.

    • I have no idea what time the meeting is supposed to start.

Idioms

  • What an idea!

    An expression used to indicate that a suggestion or idea is foolish, impractical, or ridiculous.

    • You want to have a picnic in this downpour? What an idea!

  • you have no idea

    Used to emphasize the extreme nature of a situation or experience, suggesting it is beyond the listener's imagination or comprehension.

    • You have no idea how hard I worked to finish this project.

  • what an idea!

    Used to express that a suggestion or idea is foolish or ridiculous.

    • "We should cancel all the meetings." "What an idea!"

  • someone's idea of something

    A personal conception or understanding of what something is like.

    • Working twelve hours straight is his idea of a normal workday.

  • put ideas into someone's head

    to cause someone to consider doing something, particularly something unwise or foolish, that they had not considered before.

    • Don't put such unrealistic ideas into his head, he's very gullible.