Most appurtenant is a term used to describe something that is closely related or pertinent to a particular situation or context. Antonyms for this phrase would be words that represent the opposite or unrelated concepts. Some possible antonyms for most appurtenant include irrelevant, unrelated, detached, inconsequential, peripheral, unconnected, and inapplicable. These words indicate a lack of relevance or connection to a given situation, as opposed to most appurtenant, which implies a high degree of relevance and importance. Using antonyms for most appurtenant could help writers and speakers emphasize the degree to which a particular concept or idea is extraneous or irrelevant to a given situation.