Bloke, unimportant individual, idiot. Plural: чмара. Probably loaned from Yiddish שמאָק (shmok), just as American slang schmo. Sometimes interpreted as the initials of человек московской области (person from the Moscow region), that Moscow residents look down upon.
я тупое чмо… в понедельник иду на пересдачу…
I’m a stupid git… on Monday I must retake the exam…
(Maria_Haritonova @ twitter.com, 06/2010)

