The antonyms for the word "most consummated" are "least accomplished," "unfinished," and "rudimentary." These words imply that something is not fully developed, has not been completed, or is lacking in some way. While "most consummated" suggests a high level of achievement, its antonyms imply the opposite. For example, a project can be labeled as "least accomplished" if it is still in its early stages or if it has not fulfilled its intended purpose. Similarly, a task can be considered "unfinished" if it has only been partially completed, while something that is "rudimentary" is in its most basic or elementary stage.