A metaphor is a figure of speech that describes one thing, concept, or action in terms of another one. A metaphor interacts with language intimately, creating relationships between things and ideas not recognized before. When a metaphor is the exact opposite of what it describes, it is called a collusion or a collision.
Although a metaphor is quite like a simile, it does not use words of resemblance such as "like" or "as" when it describes something.
Metaphors are either plain or implied. “A whirlwind of ideas” is a plain metaphor. “The numbers rained on him,” “His smile sinned when he looked at her,” and “Jane knifed my wound” are implied metaphors. Implied metaphors are cherished by poets and writers more than the plain ones. Since they are usually made with verbs, they bring life and excitement to an expression. Yet, plain or implied, all metaphors can be overused or abused like other good things.
At the beginning, when I tried to write poetry, I had a run-in with metaphors, only because I loved metaphors a lot. I thought they worked wonders, and since I believed metaphors were my strength, I used them too often and too indiscriminately.
Imagine a Christmas tree with decorations building up to a single shining star, which has a beautiful meaning in its fundamental nature. Well, my Christmas tree had many stars all around it with all of them fighting with that star on top for brightness, so much so that my poems became disorientated in a traffic jam of metaphors.
I stopped my romp with metaphors when a wonderful teacher pointed out to me, ever so gently, what I had been doing. I will forever be grateful to her as long as I use metaphors. She told me to use one master metaphor, and if I felt like adding extras, I should make the additional metaphors work under that one master.
Now, I go with her formula especially in a short poems; one central metaphor with all the other less significant ones building up to it. In other words, for each Christmas tree there needs be only one very bright star on top.
With a metaphor one can express an idea more pointedly and more delicately than one can express by using a roomful of adjectives and adverbs. For example, an amateur could be saying this:
“When he moved the position of his cap, it was visible that his head was covered by white hair, which was holy, sacred, saintly, distinct, untainted, not dirtied, much adored, spiritually aristocratic, and shining brightly with a circular light.”
Here is how a great poet has said it with a metaphor so eloquently.
“And white the unpigmented
Halo of his hair
When he shifted his cap:”
from Night Game by Robert Pinsky
Let us look at the word metaphor. Meta means across, phor means carry something like a ferry. So, a metaphor must “carry across” a meaning by using a physical image which stands for an abstract thought.
The poet Jane Yolen--in an interview--said:
"In Greece the word metafora is a kind of moving van and so as you drive around, you see trucks with METAFORA on the side. They are shifting a lot of stuff under the watchful eye of the stone-draped ladies of the Parthenon. There's a poem there."
Jane Yolen was so right. Where there is a good metaphor that is wisely used, there is a poem there.