The phrase "take up gauntlet" means to accept a challenge or confront a situation boldly. Antonyms for this phrase would be to refuse, reject, avoid, or retreat from a challenge. These terms imply a lack of courage, confidence, or willingness to face a difficult situation or conflict. Other antonyms could include surrender, submission, and defeat, which suggest giving up without putting up a fight. Overall, while taking up the gauntlet implies a daring and bold approach to a challenge, its antonyms suggest a more timid and passive response.