Suppose we’re discussing a quote, and I refer to a figure used to embellish an otherwise trite piece of writing. Am I being lazy in not calling it a figure of speech? Or am I applying a figure of speech (synecdoche, perhaps) to the phrase “a figure of speech” to get a shortening?
It may be a bit of both, however, it also looks like figure — meaning tricks of the rhetorical and linguistic trade — was used in that sense first, and that the expression a figure of speech came later. This is what some internet-and-book hopping has thrown up.
First, the linguistics approach: a quick jaunt to the OED Online.
The word figure has many meanings. The particular sense used in figure of speech is found under number 21, in section V, of the entry for figure, n.
V. In various uses, representing the technical applications of Greek σχῆμα.
21. Rhetoric.
a. Any of the various ‘forms’ of expression, deviating from the normal arrangement or use of words, which are adopted in order to give beauty, variety, or force to a composition; e.g. Aposiopesis, Hyperbole, Metaphor, etc. Also, figure of speech.
Indeed, searching for figure of speech redirects to this entry.
The Greek word σχῆμα refers to form or figure. The earliest of the examples given in the OED under 21.a comes from Chaucer.
c1386 Chaucer Clerk’s Prol. 16 Your termes, your coloures, and your figures, Kepe hem in store, til [etc.].
A Quiver Of Quotes 