METAPHOR, in rhetoric, a trope, by which we put a strange word for a proper word, by reason of its resemblance to it; or it may be defined, a simile or comparison intended to enforce and illustrate the thing we speak of, without the signs or forms of comparison. Thus, if we say, God is a shield to good men, it is a metaphor; because the sign of comparison is not expressed, though the resemblance which is the foundation of the trope, is plain; for as a shield guards him that bears it, against the attacks of an enemy, so the providence and favour of God protects good men from malice and misfortunes: but if the sentence be put thus, God is as a shield to good men, then it becomes a simile or comparison.