malaphor

noun

1. (rare)An idiom blend: an error in which two similar figures of speech are merged, producing an often nonsensical result.

   “What I conclude from this admittedly narrow data base is that, while the malaphor flourishes in bureaucratic compost, it will grow just about anywhere. The following malaphors are my pick of the letters. They were uttered in the home, on the farm, in the street.”

   “Among Swift's favorite malaphors are "He's a ragged individualist"; "I was up at the crank of dawn"; and "He's a fly in the oatmeal."”