Source : Webster's Revised Unabridged Dictionary (1913)

Crossly \Cross"ly\, adv.
   Athwart; adversely; unfortunately; peevishly; fretfully; with
   ill humor.

Source : WordNet®

crossly
     adv : in an ill-natured manner; "she looked at her husband
           crossly" [syn: {grouchily}, {grumpily}]