The Collaborative International Dictionary of English v.0.48:
Mostly \Most"ly\, adv. For the greatest part; for the most part; chiefly; in the main. [1913 Webster]WordNet (r) 3.0 (2006):
mostly adv 1: in large part; mainly or chiefly; "These accounts are largely inactive" [syn: largely, mostly, for the most part] 2: usually; as a rule; "by and large it doesn't rain much here" [syn: by and large, generally, more often than not, mostly]