a bad apple

a bad apple

A person who negatively impacts an entire group of people through his or her words or actions. Taken from the proverb "a bad apple spoils the bunch. Jeremy is really a bad apple. After five minutes with my usually well-behaved kids, they're all acting out.
See also: apple, bad

a bad/rotten apple

one bad person in a group of people who are good You'll find the occasional rotten apple in every organization.
See also: apple, bad