【Compliment】 , 【flattery】 , 【adulation】 all denote praise addressed directly to a person.
A 【compliment】 is a courteous expression of commendation and may be either sincere or merely formal.
【Flattery】 implies insincerity in 【compliment】 or a play upon self-love or vanity by means of artful or obsequious praise.
【Adulation】 adds to 【flattery】 the implications of servility or fulsomeness.