The Collaborative International Dictionary of English v.0.48:
Hebdomadally \Heb*dom"a*dal*ly\, adv. In periods of seven days; weekly. --Lowell. [1913 Webster]WordNet (r) 3.0 (2006):
hebdomadally adv 1: without missing a week; "she visited her aunt weekly" [syn: hebdomadally, weekly, every week, each week]