hebdomad

[ heb-duh-mad ]
/ ˈhɛb dəˌmæd /

noun

the number seven.
a period of seven successive days; week.

Origin of hebdomad

1535–45; <Latin hebdomad-<Greek (stem of hebdomás week), equivalent to hébdom(os) seventh (see hepta-) + -ad--ad1
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British Dictionary definitions for hebdomad

hebdomad
/ (ˈhɛbdəˌmæd) /

noun

obsolete the number seven or a group of seven
a rare word for week

Word Origin for hebdomad

C16: from Greek, from hebdomos seventh, from heptas seven
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012