The phrase "give thumbs down to" implies disapproval or rejection of something. Its antonym would be "give thumbs up to," which indicates approval and acceptance. Other possible antonyms for this phrase could include "support," "recommend," "approve," "endorse," or "commend." These words all convey a positive sentiment towards an idea, object or action. In contrast, "disapprove," "reject," "oppose," "denounce," or "condemn" could be considered as synonyms for "give thumbs down to," since they all suggest negative feelings and opposition towards something. Understanding the nuances of these antonyms can improve our communication skills and help us express ourselves clearly and accurately.