Full Idea
Some of my thoughts are like images of things; to these alone does the word 'idea' properly apply, as when I think of a man, or a chimera, or the sky, or an angel, or God.
Clarification
A 'chimera' is a mythological animal
Gist of Idea
True ideas are images, such as of a man, a chimera, or God
Source
René Descartes (Meditations [1641], §3.37)
Book Reference
Descartes,René: 'Philosophical Essays and Correspondence', ed/tr. Ariew,Roger [Hackett 2000], p.114
A Reaction
Descartes is obviously aware of a problem with the application of the word 'idea'. This definition seems rather narrow (and visual), but it is certainly confined to concepts, and does not expand to include propositions.