say it: ahy-DEE-uh
idea is a noun meaning "the content of cognition; the main thing you are thinking about". It carries 5 recorded senses.
the content of cognition; the main thing you are thinking about
“it was not a good idea”
“the thought never entered my mind”
an approximate calculation of quantity or degree or worth
“an estimate of what it would cost”
“a rough idea how long it would take”
(music) melodic subject of a musical composition
“the theme is announced in the first measures”
“the accompanist picked up the idea and elaborated it”
music
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for idea come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.