Up till is a phrase that is commonly used to indicate a certain time period or limit. It can, however, become repetitive and cliched over time. Therefore, it might be worthwhile to expand one's vocabulary and learn some synonyms for the phrase. Some possible alternatives could include until, until now, hitherto, heretofore, so far, up to the present, or to this point. Using synonyms can help to add variation and interest to one's writing or speech while still getting the same message across. Ultimately, the key is to find a synonym that feels natural and fits the context of the sentence or conversation.