To possess something is to have or own it. You can possess a physical object, you can possess a particular quality or skill, or you can possess control or influence over someone.
Related words are possessive (describing those who hold onto people or things in a controlling way), and possessed, as in a person being possessed by an idea or even by a demon. This verb is from Middle French posséder "to own," from Latin possidēre, from potis "able, having the power" plus sedēre "to sit."
Definitions of possess
have ownership or possession of
have as an attribute, knowledge, or skill
“he possesses great knowledge about the Middle East”
enter into and control, as of emotions or ideas
“What possessed you to buy this house?”
“A terrible rage possessed her”