What does "mangar" mean?

It’s a trough or an open box in which feed for livestock is placed.

That’s a “manger”

There are a few definitions for the word … the Urban dictionary lists it as a type of cigar, and a male cougar (not the animal - the slang term for older women attracted to younger men, but in this case, it’s an older man after younger women). A rough translator states that it means “to steal”. I think the best thing to do, is just ask them what it means.