WordWeb Online

1. Having two purposes; twofold
   "our double-barreled desire to make things profitable as well as attractive";
   - double-barrelled [Brit, Cdn]
    
2. Having two barrels mounted side by side
   "a double-barreled shotgun";
   - double-barrelled [Brit, Cdn]

See also: ambiguous

Antonym: single-barrelled [US]

Encyclopedia: Double-barreled