What is a metaphor in english terms

Figure of Speech (or stylistic device or rhetorical device) is using of different styles to complement an idea, feeling or meaning. These speeches give importance, newness of expression, or clearness. The following are the figures of speeches:

Synecdoche, Anastrophe, Anaphora, Antonomasia, Personification, Simile, Analogy, Metaphor, Alliteration, Euphemism, Assonance, Idiom, Funny Metaphors, Jargon, Double Negative, Anadiplosis, Appositive, Enthymeme, Parallelism,  Adjunction, Antithesis, Apostrophe, Climax, Metonymy, Oxymoron, Litotes, Paralipsis, Hyperbole, Onomatopoeia, Imagery, Symbol, Pun, Allegory, Tautology, Rhetoric, Zeugma, Anticlimax, Consonance, Irony, Polysyndeton, Rhetorical Question, Asyndeton, Parenthesis, Antimetabole, Epistrophe, Understatement, Chiasmus, Epithet and False Analogy.  

A metaphor is a subtle comparison of one word, relating to another.

A metaphor is a figure of speech in which a word'phrase is applied to an object/ action to which it is not literally suited.

examples:

the cats fur was a blanket of warmth. 
'her eyes were fireflies.'

and a common metaphor:
brokenhearted.

the cat's fur isn't /actually/ a blanket, but it's body heat makes the cats fur warm and snuggly.

her eye's aren't /really/ fireflies, but they're very bright and shining (indicating happiness, perhaps?)

heat's don't /actually/ break into pieces, its just hurt and sadness (and a common metaphor.)

hope this helped!!