Biz Idiom of the Day- "bad egg" bad egg Definition: A troublemaker; someone who has a bad attitude and causes trouble. Example: 1) Emily is a real bad egg -- she's always starting fights and causing trouble. 2) We have to get rid of the bad eggs in the accounting department. Etymology: In this phrase, 'egg' means 'person' or 'individual'. This is probably because the human head looks a lot like an egg. A bad egg, then, is a simply a bad person. There is a similar phrase to describe a good person - a 'good egg'. http://www.peakenglish.com/slang/dailybiz.jsp (Adam's note- this could also be a bad apple)