The Collaborative International Dictionary of English v.0.48:
Assuredly \As*sur"ed*ly\, adv. Certainly; indubitably. "The siege assuredly I'll raise." --Shak. [1913 Webster]WordNet (r) 3.0 (2006):
assuredly adv 1: without a doubt; "the grammar schools were assuredly not intended for the gentry alone"