WordWeb Online

1. Cause to be more favourably inclined; gain the good will of
   "She managed to conciliate the angry customer";
   - pacify, lenify, assuage, appease, mollify, placate, gentle, gruntle
    
2. Come to terms
   - reconcile, patch up, make up, settle
    
3. Make (one thing) compatible with (another)
   "The scientists had to conciliate the new results with the existing theories";
   - accommodate, reconcile

Derived forms: conciliating, conciliated, conciliates

Type of: agree, calm, calm down, concord, concur, harmonise [Brit], harmonize, hold, lull, quiet, quieten [Brit], still, tranquilize [N. Amer], tranquillise [Brit], tranquillize