He is a heavy eater of beef. Me thinks it doth harm to his wit.
—Shakespeare, "Twelfth Night"
conceit
A fanciful poetic image or metaphor that likens one thing to something else that is seemingly very different. An example of a conceit can be found in Shakespeare's sonnet "Shall I compare thee to a summer's day?" and in Emily Dickinson's poem "There is no frigate like a book."