The Collaborative International Dictionary of English v.0.48:
Baneful \Bane"ful\, a. Having poisonous qualities; deadly; destructive; injurious; noxious; pernicious. "Baneful hemlock." --Garth. "Baneful wrath." --Chapman. [1913 Webster] -- Bane"ful*ly, adv. --Bane"ful*ness, n. [1913 Webster]WordNet (r) 3.0 (2006):
banefully adv 1: in a noxiously baneful way; "this banefully poisoned climate" [syn: banefully, perniciously]