The Collaborative International Dictionary of English v.0.48:
Improvidently \Im*prov"i*dent*ly\, adv. In a improvident manner. "Improvidently rash." --Drayton. [1913 Webster]WordNet (r) 3.0 (2006):
improvidently adv 1: in an improvident manner; "he lived improvidently for the moment" [ant: providently]