means Something you have, hold, or legally own — whether an object, property, or a state of being controlled by something (like a feeling or a spirit).

from From Latin possessio, from possidere 'to occupy, hold,' built from potis 'able, powerful' (the same root behind 'potent' and 'possible') plus sedere 'to sit.' So at heart, to possess is to 'sit as master' over a thing — which makes the essence above quietly true, since sitting on something long enough is how it starts sitting on you. The word reached English through Old French in the medieval period.