idea

noun

ī-ˈdē-ə 

-ˈdēə,

also

ˈī-(ˌ)dē-ə 

 or  ˈī-dē

1

: a formulated thought or opinion

has some strange ideas

"I thought he'd help." "What gave you that idea?"

2

: whatever is known or supposed about something

a child's idea of time

He has a clear idea of his responsibilities.

I have no idea what you're talking about.

3

: the central meaning or chief end of a particular action or situation

The idea of the game is to get the lowest score.

I get the idea. [=I understand]

(informal) Hey! What's the big idea? [=why are you doing that?]

4

a

: a plan for action : design

Leaving early is a good idea.

Don't put ideas into his head. [=make him think about doing something he shouldn't]

b

: a standard of perfection : ideal

A quiet night at home is my idea of a good time.

5

philosophy

a

: a transcendent entity that is a real pattern of which existing things are imperfect representations

b

: an entity (such as a thought, concept, sensation, or image) actually or potentially present to consciousness

6

a

: an indefinite or unformed conception

I can't remember anything. I remember only ideas and sensations.

—James Joyce

b

obsolete : an image recalled by memory

7

Christian Science : an image in Mind

8

archaic : a visible representation of a conception : a replica of a pattern

idealess

ī-ˈdē-ə-ləs 

-ˈdēə-

 also  ˈī-(ˌ)dē-ə-

 or  ˈī-dē-

adjective

Synonyms of idea

• concept
• thought
• notion
• impression
• conception

Choose the Right Synonym for idea

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

Examples of idea in a Sentence

My idea is to study law.

Starting her own business seemed like a good idea at the time, but it turned out badly.

Whose idea was it to leave so early?

My idea was that if we left early we could beat the crowd.

Buying the car was a bad idea.

I have some ideas for redecorating the room.

He has an idea for a movie.

I'm not sure what to do next. Do you have any ideas?

She's always full of new ideas.

It's a good idea to talk to people who have actually been there.

Recent Examples on the Web

Seven decades later, these ideas are mainstream in both Israeli and US discourse. —Literary Hub, 3 Nov. 2025

One idea that still looks elegant but adds a little something-something? —Luz García, Glamour, 2 Nov. 2025

Closing that gap will be an overarching idea for Cubs president of baseball operations Jed Hoyer and his front office over the coming months. —Patrick Mooney, New York Times, 2 Nov. 2025

His critics on the left say these ideas are unrealistic — even in a liberal bastion like New York City. —Elena Moore, NPR, 2 Nov. 2025

Word History

Etymology

Middle English, from Latin, from Greek, from idein to see — more at wit

First Known Use

14th century, in the meaning defined at sense 5a

Phrases Containing idea

• big idea
• can't stand the thought/idea
• get the idea
• get the wrong idea
• have no idea
• I have no idea
• nice idea
• not have the faintest idea/notion
• not have the faintest/slightest idea
• put that idea out of your head
• the idea
• the idea behind
• what's the big idea
• you have no idea

Rhymes for idea

• chia
• mia
• pia
• rhea
• shia
• stria
• thea
• zia
• aliya
• aliyah
• althea
• apnoea

Kids Definition

idea

noun

ī-ˈdē-ə 

ˈīd-(ˌ)ē-ə

1

: a plan of action : intention

my idea is to study law

2

: something imagined or pictured in the mind : notion

form an idea of a place from reading

3

: a central meaning or purpose

the idea of the game is to score goals

4

: comprehension sense 2

had no idea what he meant

5

: an opinion or belief

has some strange ideas

idealess

ī-ˈdē-ə-ləs 

adjective

Medical Definition

idea

noun

ī-ˈdē-ə  ˈīd-(ˌ)ē-ə 

1

: an entity (as a thought, concept, sensation, or image) actually or potentially present to consciousness

2

: a formulated thought or opinion