The word underpinning means the basis or foundation of something. Its antonyms include terms like disprove, contradict, undermine, and weaken. Disprove suggests that the underpinning is untrue or incorrect, whereas contradict implies that the foundation of a claim or argument is at odds with the given evidence. Undermining refers to the gradual chipping away of the underlying support, whereas weakening describes a gradual reduction in strength. Other antonyms include collapse, destitution, and failure, which all suggest a sudden and complete loss of support or foundation. Together, the antonyms of underpinning encompass a range of scenarios where the foundation or basis of something is called into question.