Hebdomad and Sevens

Hebdomad noun - Any period of seven consecutive days.

Sevens and hebdomad are semantically related In some cases you can replace term "Sevens" with "Hebdomad", this nouns are similar.

Sevens noun - A card game in which you play your sevens and other cards in sequence in the same suit as the sevens; you win if you are the first to use all your cards.

Hebdomad and sevens are semantically related in seven of something topic. You can use "Hebdomad" instead a noun "Sevens".