A figure of speech that implicitly compares two unlike things without using 'like' or 'as'. Often contrasted with 直喩 (simile).
See also: 隠喩
The expression 'Life is a journey' is an example of a metaphor.
Metaphors are often used in poetry.
From 暗 (hidden, implicit) + 喩 (figure of speech, comparison). The term was coined to describe an implied comparison, as opposed to an explicit one (直喩).