The antonyms for the phrase "most altogether" can be interpreted in a few different ways. If we consider "most" as meaning "almost all" then antonyms could include "few," "some," or "minority." If we consider "altogether" to mean "completely" or "entirely," then antonyms could include "partially," "incompletely," or "in part." Other antonyms could include "scarcely," "hardly," or "rarely" if we are considering the quantity or frequency of something. Ultimately, the antonyms for "most altogether" will depend on the context in which it is being used and the specific meaning of the words in that context.