hebdomadal
Concise Oxford English Dictionary © 2008 Oxford University Press:
hebdomadal /hɛbˈdɒməd(ə)l/
▶adjective formal weekly.
– origin C17: from late L. hebdomadalis, from Gk hebdomas, hebdomad- ‘the number seven, seven days’, from hepta ‘seven’.
'hebdomadal' also found in these Oxford entries:

