The Collaborative International Dictionary of English v.0.48:

Curtly \Curt"ly\ (k[^u]rt"l[y^]), adv.
   In a curt manner.
   [1913 Webster]

WordNet (r) 3.0 (2006):

curtly
    adv 1: in a curt, abrupt and discourteous manner; "he told me
           curtly to get on with it"; "he talked short with
           everyone"; "he said shortly that he didn't like it" [syn:
           curtly, short, shortly]

Moby Thesaurus II by Grady Ward, 1.0:

32 Moby Thesaurus words for "curtly":
   abruptly, aphoristically, bearishly, bluffly, bluntly, boorishly,
   brashly, briefly, brusquely, cavalierly, churlishly, compendiously,
   concisely, crisply, crustily, economically, gruffly, harshly,
   in brief compass, laconically, nastily, pithily, pointedly,
   sententiously, sharply, shortly, snippily, sparely, succinctly,
   summarily, synoptically, tersely