The word "re-occurs" refers to something that happens again or repeats itself. Conversely, the antonym for this word would be a term that describes something that only happens once or does not repeat itself. Some common antonyms for "re-occurs" include terms like "occurs once," "happens once," "is a one-off," "is unique," or "is a singular event." These terms all describe something that is not repeated, unlike "re-occurs," which implies that there has been a prior occurrence of this event. By understanding the antonyms for "re-occurs," we can more clearly describe specific events and their occurrence rates.