definition of
idea

[1] #1 idea n. [thought] the content of cognition; the main thing you are thinking about; "it was not a good idea"; "the thought never entered my mind". wn

[2] #2 idea n. [mind] your intention; what you intend to do; "he had in mind to see his old teacher"; "the idea of the game is to capture all the pieces". wn

[3] #3 idea n. a personal view; "he has an idea that we don't like him". wn

[4] #4 idea n. [estimate, estimation, approximation] an approximate calculation of quantity or degree or worth; "an estimate of what it would cost"; "a rough idea how long it would take". wn

[5] #5 idea n. [theme, melodic theme, musical theme] (music) melodic subject of a musical composition; "the theme is announced in the first measures"; "the accompanist picked up the idea and elaborated it". wn