Where the hell did you pick up this word? I've never ever heard it in my 24 years long Russian life

Well, as for the word my Russian brain imagined a hole in a road but apparently the Russian definition dictionary disagrees with me. It says this:

остатки семян масличных растений после выжимания из них масла; жмых, дуранда.

And BIG SUPRISE the Google Translate gives up the word "oilcake" for жмых

Well, okay let's do that the old-fashioned way I mean by explaing the word. So this word illustrates what is left after oily seeds (like sunflower seeds) are squashed to get oil out of them

I hope this helps but I'd like to warn you. I'd never ever use избоина for that meaning I'd use жмых instead