cat·a·chre·sis 
(k
ăt
′ə-kr
ēs
ĭs)
n. pl. cat·a·chre·ses (-s
ēz)
1. The misapplication of a word or phrase, as the use of blatant to mean "flagrant."
2. The use of a strained figure of speech, such as a mixed metaphor.
[Latin catachrēsis, improper use of a word, from Greek katakhrēsis, excessive use, from katakhrēsthai, to misuse : kata-, completely; see CATA- + khrēsthai, to use; see gher-2 in the Appendix of Indo-European roots.]
cat′a·chrestic (-krĕstĭk), cat′a·chresti·cal (-tĭ-kəl) adj.
cat′a·chresti·cal·ly adv.