WordWeb Online

1. A male deer, especially an adult male red deer
   - hart
    
2. Adult male deer

1. [N. Amer] Attend a dance or a party without a female companion
    
2. Give away information about somebody
   - denounce, tell on, betray, give away, rat [informal], grass, shop [informal], snitch [informal], squeak [informal]
    
3. Watch, observe, or inquire secretly
   - spy, snoop, sleuth

1. Of a man, attending a social function without a date
   "My brother went stag to prom because he couldn't find a date"

Derived forms: stags, stagged, stagging

Type of: American elk, buck, Cervus elaphus, elk [N. Amer], inform, monitor, red deer, supervise, wapiti, watchdog

Encyclopedia: Stag