When it comes to describing slow movements, "turtle's pace" is a commonly used phrase. However, there are several synonyms that can be used to add variety to your writing. For instance, you may use "snail's pace," "glacial pace," or even "molasses-like." Alternatively, you may go creative and use descriptive phrases such as "crawling like a centipede" or "moving like a sloth." Another option is to use metaphors, such as "moving at a geologic speed" or "creeping like a glacier." Using synonyms for "turtle's pace" can add vividness and interest to your writing and help avoid repetition.