What is the common noun for harem?

There isn't a single perfect common noun for "harem" because its meaning is complex and has evolved over time. Here are some options depending on the specific context:

General sense of a group of women:

* Group

* Household

* Women

* Wives

* Concubines (though this has a negative connotation)

More specific, historical context:

* Seraglio (specifically referring to a royal household in the Ottoman Empire)

* Gynaeceum (a women's living space in ancient Greek households)

Figurative use:

* Entourage

* Following

The best option depends on the specific context and the nuance you want to convey.