The antonyms for the word "re-current" are "one-time", "single", "non-recurring", "singular", and "unique". These words mean that an event or occurrence is not repeated or happens only once. For example, a one-time job offer means that the job is not going to be repeated or come up again. A non-recurring event could be a rare annual festival celebrated only once a year. A singular achievement means that it is a unique accomplishment, and no other similar achievement has been made before. Overall, these words are used to denote that something is not repeated and happens only once.