A meek and timid person can be called a nebbish. If you're too scared to speak up when someone cuts in front of you as you wait in line for a movie, your date might call you a nebbish.
Nebbish is most often used to describe a man, especially one who is so mild and submissive that other people tend to feel sorry for him. A nebbish isn't capable of accomplishing much or defending himself, so he often finds himself scorned or pitied. Nebbish comes from a Yiddish word, nebekh, "poor thing," and it's been used in English slang since the late 19th century.