Pre-possessing typically describes something or someone that is attractive or captivating in appearance, manner or character. Therefore, some antonyms for pre-possessing would include unattractive, unappealing, off-putting, repulsive, and ugly. Other antonyms for pre-possessing could include uncharming, boring, unremarkable, plain, and unimpressive. People, places, or things, that don't have any of the qualities typically associated with being pre-possessing, can fall under the category of antonyms for the word. Overall, antonyms for pre-possessing essentially describes anything that is lacking in attractiveness, charm, and appeal.