WordWeb Online

1. A mark against a person for misconduct or failure; usually given in school or armed forces
   "ten demerits and he loses his privileges"
    
2. The quality of being inadequate or falling short of perfection
   "they discussed the merits and demerits of her novel";
   - fault

Derived forms: demerits

Type of: brand, mark, stain, stigma, worth

Antonym: merit

Encyclopedia: Demerit