WordWeb Online

1. (law) lessen or to try to lessen the seriousness or extent of
   "The circumstances palliate the crime";
   - extenuate, mitigate
    
2. Provide physical relief, as from pain
   "This pill will palliate your headaches";
   - relieve, alleviate, assuage

Derived forms: palliates, palliated, palliating

Type of: ameliorate, amend, apologise [Brit], apologize, better, excuse, improve, meliorate, mend, rationalise [Brit], rationalize