A sentence used to express the relationship of words, : can mean "is to" and :: can mean "as"
Arm is to leg as hot is to cold
have sex : lose virginity :: jumping off a cliff : death
A comparison between two unrelated things; does NOT use the words "like" or "as."
Note to all of the people out there who only think they understand grammar:
A comparison using "like" or "as" (definition #2) is a SIMILE.
A sentence used to express the relationship of words (definition #3) is an ANALOGY.
"America is a melting pot" is a metaphor.
"Life is like a box of chocolates" is a simile.
"Pink is to red as gray is to black" is an analogy.
A poetic device used to draw comparison, or illustrate a parallel relationship between two different subjects. More or less the same as a simile, except omitting the word "like;" as in the following example- METAPHOR- Life is a box of chocolates./SIMILE- Life is like a box of chocolates. Confusion over these two techniques has resulted in untold disasters throughout the history of language.
The guy in the cowboy hat said, "Life is a metaphor for itself," but he's bi-polar and thinks he's Jesus, so don't pay no attention to him.
The word that Christians use to describe contradictions and mistakes in the bible.
"So, the Earth is flat, according to the bible, Tony?"
"but, “When the earth totters, with all its inhabitants, it is I who keep its pillars steady.” — Psalm 75:3"
"thats a metaphor, dude"
A comparison using "like" or "as"
Metaphors: Alice looks like a pig when she eats
Alice is as big as an elephant