Metaphor

n. simile, poetic substitution of one thing for another in order to suggest comparison or resemblance; mundane thing that is used as a symbol for an abstract concept

Metaphor (from the Greek: metapherin) is language that directly compares seemingly unrelated subjects. In the simplest case, this takes the form: "The [first subject] is a [second subject]." More generally, a metaphor is a rhetorical trope that describes a first subject as being or equal to a second subject in some way. Thus, the first subject can be economically described because implicit and explicit attributes from the second subject are used to enhance the description of the first. This device is known for usage in literature, especially in poetry, where with few words, emotions and associations from one context are associated with objects and entities in a different context.
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Noun
1. a figure of speech in which an expression is used to refer to something that it does not literally denote in order to suggest a similarity
(hypernym) trope, figure of speech, figure, image
(hyponym) dead metaphor, frozen metaphor

(n.)
The transference of the relation between one set of objects to another set for the purpose of brief explanation; a compressed simile; e. g., the ship plows the sea.
  

image