The antonyms for the phrase "at start" are numerous, and they include "at the end," "in the middle," "afterward," "subsequently," "then," and "eventually." These terms are used to describe a situation when a sequence of events or actions is being described. At the start, however, is typically used to describe the opening of a process or an event, and these alternatives describe the opposite, the conclusion, the last, the final, or the end result of that activity. Using these terms helps to give clarity and context to the meaning and flow of language.