Antonyms for the word "prize-winning" can vary depending on the context of the word. Some possible antonyms for "prize-winning" may include "unsuccessful," "losing," "inferior," "mediocre," "subpar," "unremarkable" or "unexceptional." When used in a more specific context such as "prize-winning author," the antonyms can include "unknown," "unpublished," "unacknowledged," "non-award-winning," or "amateur." When it comes to defining the word "prize-winning" in terms of qualities or traits, antonyms can mean the opposite or absence of these qualities such as "unimpressive," "uninspired," "uncreative," "unremarkable," or "unworthy.