The term "oftrepeated" suggests something that is said or done frequently. Its antonyms include infrequent, rare, occasional, intermittent, and sporadic. Infrequent refers to something that seldom happens or occurs at long intervals. Rare denotes something that is very unusual or scarce. Occasional suggests something that happens from time to time, but not regularly. Intermittent implies something that occurs at irregular intervals with occasional breaks. Sporadic denotes something that happens at intervals but with no definite pattern. Therefore, by using words with the opposite meaning of "oftrepeated," one can convey the ideas of rarity, exceptionality, and irregularity.