There are several synonyms one can use for the phrase "share an address". Such alternatives include, share a residence, share a home, share a house, share a dwelling, share a domicile, share a living space, share an abode, share a habitat, share a lodging, and share a place of abode. All of these suggest that two or more people are residing in the same place. It could be roommates sharing an apartment or a family living under one roof. Using these synonyms can help spice up your writing and prevent redundancy. They can also allow for a more precise description of the living arrangements.