The term "most boneheaded" refers to an action or behavior that is extremely stupid or foolish. To find antonyms for this phrase, the focus should be on terms that represent a high level of intelligence or cleverness. Some good antonyms for "most boneheaded" could include intelligent, astute, shrewd, savvy, or wise. Other options might include terms such as brainy, bright, sharp, or ingenious. These terms all represent a high level of mental acuity, suggesting an opposite of the "most boneheaded" behavior. It is important to note that while "most boneheaded" may be a colloquial term, the idea of intelligence and foolishness is one that can be expressed in many ways, using a wide range of vocabulary.