It is a Yiddish term for someone who is meek and mild as well as very careful in the decision making process. It is often used to define someone as a nerd or a loser.

Nebbish is an American word, not a Hebrew or Yiddish one. They pronounce it that way because of the difficulty in enunciating the "kh" sound. The original word is "nebbikh", a… Yiddish word meaning "pitiable"; originating in the Hebrew "navokh" which means confused. I don't think the Yiddish colloquialism has a female counterpart. (MORE)