One I was thinking about today is, “Put on the dog.” Of course, the figurative meaning of putting on the dog is to make an ostentatious show, like really gussy the thing up.
Sidebar: what does it mean to “gussy” something up anyway???
I looked up the etymology of putting on the dog, but only found a few language myths debunked. Does anyone have any thoughts or guesses on the origins of the phrase? Just wondering.