WordWeb Online

1. Tending to soothe or tranquilize
   "took a hot drink with tranquillising properties before going to bed";
   - ataractic, ataraxic, sedative, tranquilizing [N. Amer], tranquillizing [Brit], tranquillising [Brit]

1. Make calm or still
   "tranquillise the dragons of worry and fear";
   - calm, calm down, quiet, tranquilize [N. Amer], tranquillize, quieten [Brit], lull, still
    
2. Cause to be calm or quiet as by administering a sedative to
   "The patient must be tranquillised before the operation";
   - sedate, calm, tranquilize [N. Amer], tranquillize

See also: depressant

Type of: affect, comfort, console, solace, soothe