The phrase "most oft repeated" refers to something that is frequently and repeatedly said or done. The antonyms for this term might include infrequent, seldom, rare, occasional, sporadic, or infrequent. These words suggest that the action or statement in question occurs with less frequency, perhaps only occurring once in a while or very rarely. For example, rather than being "most oft repeated," it may be "infrequently mentioned" or "occasional." Using antonyms like these can help to add nuance and variation to your writing, preventing repetition and creating a more interesting, intricate style.