The Collaborative International Dictionary
Hebdomadal \Heb*dom"a*dal\, Hebdomadary \Heb*dom"a*da*ry\, a. Consisting of seven days, or occurring at intervals of seven days; weekly.
Douglas Harper's Etymology Dictionary
1610s, from Latin hebdomadalis, from hebdomas, from Greek hebdomas "the number seven; a period of seven (days)," from hepta "seven" (from PIE *septm; see seven) + -mos, suffix used to form ordinal numbers, cognate with Latin -mus. In later use as pedantic humor.
Wiktionary
a. 1 (context obsolete English) Lasting seven days. 2 weekly, occurring once a week.
WordNet
adj. appearing or occurring every seven days; "hebdomadal (or weekly) newspapers"; "hebdomadal meetings" [syn: hebdomadary]
Usage examples of "hebdomadal".
Or do they deem their hebdomadal freedom more complete, because their wives and daughters are shut up four or five times in the day at church or chapel?
Now, the queue had undergone its hebdomadal combing just an hour before Raoul announced his intention to proceed to Naples in the yawl, and it would have been innovating on the only thing that Ithuel treated with reverence to undo the work until another week had completed its round.
And even while holding that key in his hand, he did another strange thing, not to be believed by senate-house or hebdomadal board.
And, indeed, for him, there was little left to talk about, save the everlasting pettinesses of hebdomadal board, or something which he hated still more.