The Collaborative International Dictionary of English v.0.48:
Grumpily \Grump"i*ly\, adv. In a surly manner; sullenly. [Colloq.] [1913 Webster]WordNet (r) 3.0 (2006):
grumpily adv 1: in an ill-natured manner; "she looked at her husband crossly" [syn: crossly, grouchily, grumpily]