a figure of speech in which a term or phrase is applied to something to which it is not literally applicable in order to suggest a resemblance, as in “A mighty fortress is our God.”Compare mixed metaphor, simile(def 1).
something used, or regarded as being used, to represent something else; emblem; symbol.
Origin of metaphor
1525–35; < Latinmetaphora < Greekmetaphorá a transfer, akin to metaphérein to transfer. See meta-, -phore
late 15c., from Middle French metaphore (Old French metafore, 13c.), and directly from Latin metaphora, from Greek metaphora "a transfer," especially of the sense of one word to a different word, literally "a carrying over," from metapherein "transfer, carry over; change, alter; to use a word in a strange sense," from meta- "over, across" (see meta-) + pherein "to carry, bear" (see infer).
The comparison of one thing to another without the use of like or as: “A man is but a weak reed”; “The road was a ribbon of moonlight.” Metaphors are common in literature and expansive speech. (Comparesimile.)