The word "most all-purpose" is not inherently associated with any specific antonyms. However, to find antonyms for the concepts conveyed by the phrase, one might consider words that indicate specificity or limited functionality. For example, "specialized," "narrow," "restricted," and "limited" could be considered antonyms for "all-purpose." Another approach might be to consider the various uses or contexts in which "all-purpose" might be used and explore antonyms for those specific contexts. For instance, an "all-purpose" cleaner might have antonyms like "stain remover" or "disinfectant" depending on the specific cleaning task at hand.