The Collaborative International Dictionary of English v.0.48:

Mannerly \Man"ner*ly\, a.
   Showing good manners; civil; respectful; complaisant.
   [1913 Webster]

         What thou thinkest meet, and is most mannerly. --Shak.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Mannerly \Man"ner*ly\, adv.
   With good manners. --Shak.
   [1913 Webster]

WordNet (r) 3.0 (2006):

mannerly
    adj 1: socially correct in behavior [syn: mannerly, well-
           mannered]

Moby Thesaurus II by Grady Ward, 1.0:

25 Moby Thesaurus words for "mannerly":
   accommodatingly, attentively, chivalrously, civilly, complacently,
   complaisantly, correct, courteous, courteously, courtly,
   deferentially, gallantly, genteel, good-mannered, gracefully,
   graciously, knightly, obligingly, polite, politely, respectfully,
   urbanely, well-behaved, well-mannered, well-spoken