Courtly (-l), a.
Etymology: [From Court.]
1. Relating or belonging to a court.
2. Elegant; polite; courtlike; flattering. In courtly company or at my beads. Shak.
3. Disposed to favor the great; favoring the policy or party of the court; obsequious. Macualay.
1 other Webster entry under this spelling
Courtly, adv.
In the manner of courts; politely; gracefully; elegantly. They can produce nothing so courtly writ. Dryden
Shades of meaning
Fernald has no entry of its own for courtly; he lists it under polite.
Where he writes about it:
Courtly suggests that which befits a royal court, and is used of external grace and stateliness without reference to the prompting feeling; as, the courtly manners of the ambassador. — from polite