Catachresis

n.

1.

(Rhet.) A figure by which one word is wrongly put for another, or by which a word is wrested from its true signification; as, "To take arms against a sea of troubles". Shak. "Her voice was but the shadow of a sound." Young.

Noun

1.

catachresis - strained or paradoxical use of words either in error (as `blatant' to mean `flagrant') or deliberately (as in a mixed metaphor: `blind mouths')

rhetorical device