what an idea! Definition

idea
noun ideas

1. A thought, image, notion or concept formed by the mind.

Thesaurus: thought, concept, notion, conception, brainstorm; opinion, belief, conviction.
2. A plan or intention.

Thesaurus: intention, plan, doctrine, design, approach, programme.
3. A main aim, purpose or feature.

Example: The idea of the game is to win as many cards as possible
4. An opinion or belief.

Example: He's got the idea that no one likes him
5. A vague notion or fancy.

Example: had no idea what to do
6. Someone's conception of what is a good example of something.

Example: not my idea of fun
7. philos.
In Plato: a universal model of which all existing examples are imperfect copies.

Idiom: get ideas

colloq
To have ideas which are over-ambitious or undesirable.
Example: He got ideas above his station
Example: You should have known she'd get ideas if you went out with her

Idiom: put ideas into someone's head

To give them over-ambitious or impractical ideas.

Idiom: that's an idea

colloq
That plan is worth considering.

Idiom: the very idea

colloq
The mere thought.
Example: shuddered at the very idea of it

Idiom: the very idea! (what an idea!)

colloq
That's absurd! that's outrageous!

Idiom: what's the big idea

ironic, slang
What do you think you're doing.

Etymology: 16c, originally in sense 7: Latin and Greek, meaning ‘form' or ‘pattern'.