condominium (n.)

1714, "joint rule or sovereignty, ownership exclusive of all except the co-owners," from Modern Latin condominium "joint sovereignty," apparently coined in German c. 1700 from Latin com "with, together" (see com-) + dominium "right of ownership, property, dominion," from dominus "lord, master, owner," from domus "house" (from PIE root *dem- "house, household").

A word in politics and international law until sense of "privately owned apartment" arose in American English 1962 as a special use of the legal term.