"It is my property."
Translation:Det är min egendom.
I think you're confusing the verb "to own" and the adjective "own" which are obviously written and pronounced the same way in modern English, but slightly different words etymologically. In Swedish, they're not the same though: egen = one's own. äga = to own.
Egendom = Egen + dom = own (adj.) + dom (-hood, -ledge, -ness)