Housemate

A person who shares a house with others, typically as equals rather than family members.

Housemate combines 'house' with 'mate' from Middle Low German 'mate' meaning 'messmate' - someone who shared meals ('meat') at the same table. Originally used for sailors sharing food rations, 'mate' evolved to mean any companion or partner. The compound 'housemate' emerged in the 1960s as young adults increasingly lived in shared housing arrangements outside traditional family structures, needing a word for non-romantic, non-family cohabitants.