Full Idea
The essence of metaphor is understanding and experiencing one kind of thing in terms of another.
Gist of Idea
Metaphors understand and experience one thing in terms of another
Source
G Lakoff / M Johnson (Metaphors We Live By [1980], 01)
A Reaction
A pretty good definition, which gets us away from a mere comparison or resemblance. I'm cautious, though, about the word 'understanding' here. It seems obvious that metaphorical conceptualising could lead straight to misunderstanding.
Book Reference
Lakoff,G/Johnson,M: 'Metaphors We Live By' [Chicago 2003], p.5