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1. A group of seven.
2. A period of seven days; a week.

[Latin hebdomas, hebdomad-, the number seven, from Greek, from hebdomos, seventh, from hepta, seven; see septm̥ in Indo-European roots.]


1. obsolete the number seven or a group of seven
2. a rare word for week
[C16: from Greek, from hebdomos seventh, from heptas seven]


(ˈhɛb dəˌmæd)

1. a group of seven.
2. a period of seven days; week.
[1535–45; < Latin hebdomad- < Greek (s. of hebdomás week) =hébdom(os) seventh (see hepta-) + -ad- -ad1]
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.hebdomad - any period of seven consecutive dayshebdomad - any period of seven consecutive days; "it rained for a week"
period, period of time, time period - an amount of time; "a time period of 30 years"; "hastened the period of time of his recovery"; "Picasso's blue period"
calendar day, civil day - a day reckoned from midnight to midnight
day of the week - any one of the seven days in a week
week from Monday - a time period of a week or more; "a week from Monday will be too soon!"
weekend - a time period usually extending from Friday night through Sunday; more loosely defined as any period of successive days including one and only one Sunday
rag week, rag - a week at British universities during which side-shows and processions of floats are organized to raise money for charities
Holy Week, Passion Week - the week before Easter
shibah, shiva, shivah - (Judaism) a period of seven days of mourning after the death of close relative; "the family is sitting shiva"
References in periodicals archive ?
I am indebted to Deborah Gera for drawing my attention to this article; she also suggests that there may conceivably have been a double hebdomad of the Seven against Thebes and the Seven Champions in Thebes.
Brisson next offers a remarkably nuanced portrayal of Kronos as summit of the intellective hebdomad in Proclus's interpretation of the Chaldaean Oracles.
This is suggested in light of the fact that, as the paper explains, the hebdomad plays an important role within the neo-Pythagorean literature of Nicomachus of Gerasa, a thinker with whose writings Boethius was intimately familiar, and to whose works Boethius is often indebted.