The phrase "puts up a fight" implies resistance, opposition or defense. Its antonyms can be passive, compliant, surrender, submission, and acquiescence. Passive means not taking any action or being inactive. Compliant means obedient to rules or authority. Surrender implies giving up, adapting to the situation. Submission means accepting without resistance. Lastly, acquiescence implies agreement without enthusiasm. These antonyms are often used in contrast to "puts up a fight" to describe a person who does not resist or put up any fight in tough situations. Instead, they choose to accept and become passive or surrendered.