The Collaborative International Dictionary of English v.0.48:

Well-mannered \Well`-man"nered\, a.
   Polite; well-bred; complaisant; courteous. --Dryden.
   [1913 Webster]

WordNet (r) 3.0 (2006):

well-mannered
    adj 1: of good upbringing [syn: well-bred, well-mannered]
    2: socially correct in behavior [syn: mannerly, well-
       mannered]

Moby Thesaurus II by Grady Ward, 1.0:

20 Moby Thesaurus words for "well-mannered":
   ceremonial, ceremonious, conventional, correct, courteous,
   decorous, genteel, good-mannered, hieratic, liturgic, mannerly,
   polite, pompous, ritual, ritualistic, sacerdotal, solemn, stately,
   well-behaved, well-spoken