The term "reaches conclusion" can have many antonyms, depending on the context. Some opposite terms that come to mind include "undecided," "uncertain," "ambiguous," and "inconclusive." When someone fails to reach a conclusion, they might be stumped, unsure, or unable to make a definitive decision. Conversely, when a conclusion is reached, the opposite might be true, and the individual has successfully come to a resolution or made a final determination. In many cases, the absence of a conclusion might lead to ongoing debate or disagreement, while a clear resolution can pave the way for progress and closure.