The Collaborative International Dictionary of English v.0.48:
Surlily \Sur"li*ly\ (s[^u]r"l[i^]*l[y^]), adv. In a surly manner. [1913 Webster]WordNet (r) 3.0 (2006):
surlily adv 1: in a churlish manner; "the store owner treated his customers churlishly" [syn: churlishly, surlily]