hebdomad
noun
heb·do·mad ˈheb-də-ˌmad 
1
: a group of seven
2
: a period of seven days : week
Word History
Etymology
Latin hebdomad-, hebdomas, from Greek, from hebdomos seventh, from hepta seven — more at seven
First Known Use
1545, in the meaning defined at sense 1
- crackajack
- crackajacks
- crackaloo
- crackback
- crackbacks
- crackbrain
- crackbrained
- crackbrains
- crackdown
- crackdowns
- cracked
- cracked (on)
- cracked cocoa
- cracked down
- cracked down (on)
- cracked down on
- cracked heels
- cracked into
- cracked on
- cracked plate
- cracked stem
- cracked up
- cracked up to be
- cracked wise
- cracker