figure of speech
Definition - Any word or phrase that deviates from the normal literal use of words in order to add beauty, variety, or emphasis to a statement.

1. The common techniques for doing this have been given names, such as hyperbole, hysteron proteron, merism, and metaphor.

Example -
He has tons of money
(i.e. he has lots of money, but it probably doesn't weigh a ton).

Etymology -
The term was coined as a translation of the Latin figura orationis, which itself is a translation of the Greek term skhema tes lexeos.

Oxford English Dictionary -
Its first citation is from 1669:
"Words are sometimes encreast or diminisht by a Letter or Syllable … which are call'd Figures of Speech."
(Milton, Accedence Wks., 1851 VI. 467) )

Please comment