1. (in telephoning)
a. a call made to a number other than the one intended.
b. the number or person reached through such a call.
2. Slang.
a. the wrong person for a particular task, role, or situation: Me cook a gourmet dinner? - You've got the wrong number!
b. an inadequate, disagreeable, or repulsive person: She's OK, but her brother's a wrong number.