The word "un-often" means infrequent or seldom. Its antonyms, on the other hand, include words like frequently, regularly, often and usually. These words are used to describe actions or events that occur repeatedly or habitually over a period of time. For instance, if someone goes to the gym regularly, they are known to exercise frequently. Similarly, if a person enjoys watching movies quite often, they can be called a movie buff. The use of antonyms for "un-often" can add a positive connotation to a sentence and make it seem more uplifting and upbeat.