Nonsense! A confused mixture of unrelated things. A very cordial-sounding way to inform someone that their ideas are bafflingly ridiculous and incoherent without seeming overly impolite. It combines the senses of 'incoherent' and 'ridiculous' into a unique and useful term.
From French, meaning 'gibberish.'
Usage kinda boring, but I couldn't think of anything funny :(
Jim, CEO of Awesome Inc., looked down the long board room table at the sweating, balding man in front of him. He remained silent a moment to let the moment linger, then eyed the proposal in front of him. "Johnson, this is the last straw!" He bellowed. "I asked you for a proposal on how we could get our profits up, and you give me this gallmatias of crap! You're fired!" He picked up a red rubber stamp and stamped IMBECILE in big, bold words on the front of the page.