[ ahy-dee-uh, ahy-deeuh ]
/ aɪˈdi ə, aɪˈdiə /


Origin of idea

1400–50; < Late Latin < Greek idéā form, pattern, equivalent to ide- (stem of ideîn to see) + feminine noun ending; replacing late Middle English idee < Middle French < Late Latin, as above; akin to wit1

Related forms

i·de·a·less, adjectivepre·i·de·a, nounsub·i·de·a, noun

Synonym study

1, 2. Idea, thought, conception, notion refer to a product of mental activity. Idea, although it may refer to thoughts of any degree of seriousness or triviality, is commonly used for mental concepts considered more important or elaborate: We pondered the idea of the fourth dimension. The idea of his arrival frightened me. Thought, which reflects its primary emphasis on the mental process, may denote any concept except the more weighty and elaborate ones: I welcomed his thoughts on the subject. A thought came to him. Conception suggests a thought that seems complete, individual, recent, or somewhat intricate: The architect's conception delighted them. Notion suggests a fleeting, vague, or imperfect thought: a bare notion of how to proceed.

Word story

English idea comes from one of Seneca’s Epistles (58), written about a.d. 64 during his retirement from Emperor Nero’s court, in which the Roman philosopher uses idea in the sense of “Platonic idea, eternal archetype.” Seneca wrote idea in Latin letters; the Roman orator Cicero, about a hundred years earlier, wrote the same word, with the same meaning, but in Greek letters. Plato used the perfectly ordinary Greek noun idéa “form, shape” as a term in logic meaning “classification, principle of classification,” and in his own metaphysics to mean “ideal form, prototype.” In fact, the earliest uses of idea in English show semantic overlap with ideal. The familiar and current meanings having to do with a mental conception, notion, or image first appeared in the late 16th century.
The Greek noun idéa comes from the very common, very complicated Proto-Indo-European root weid-, woid-, wid- “to see.” In Greek the variant woid- forms the verb oîda ( woîda in some dialects), meaning “I know.” (In form, oîda is a perfect tense used to show a present state: “I have seen, I know.”)
Woidos, a noun derived from woid-, becomes veda- “knowledge” in Sanskrit ( Rig-Veda means “knowledge of the hymns, sacred stanzas”). The variant wid- forms the Greek noun idéa, and the infinitive ideîn (also wideîn ), the Latin infinitive vidēre, and the Slavic (Czech) vidět, all meaning “to see.”
Weid-, woid-, wid- become wīt-, wait-, wit- in Germanic. The suffixed form wīt-to- forms the adjective wīsaz, Old English wīs (English wise ), and Old English wīsdōm “learning” (English wisdom ). Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for idea

British Dictionary definitions for idea (1 of 2)


/ (aɪˈdɪə) /


Derived Forms

idealess, adjective

Word Origin for idea

C16: via Late Latin from Greek: model, pattern, notion, from idein to see


It is usually considered correct to say that someone has the idea of doing something, rather than the idea to do it: he had the idea of taking (not the idea to take) a short holiday

British Dictionary definitions for idea (2 of 2)


/ (aɪˈdɪə) /


another name for Form
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medicine definitions for idea


[ ī-dēə ]


Something, such as a thought or conception, that potentially or actually exists in the mind as a product of mental activity.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Idioms and Phrases with idea


see bright idea; put ideas in someone's head; what's the idea.

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.