The Collaborative International Dictionary of English v.0.48:
Incredulously \In*cred"u*lous*ly\, adv. In an incredulous manner; with incredulity. [1913 Webster]WordNet (r) 3.0 (2006):
incredulously adv 1: in an incredulous manner; "the woman looked up at her incredulously" [syn: incredulously, unbelievingly, disbelievingly] [ant: believingly, credulously]