The word "un-arms" refers to the removal or disarming of weapons. Antonyms for un-arms would be words that mean the opposite, or words that describe the act of arming or equipping with weapons. Some possible antonyms for un-arms include words like arm, equip, prepare, gear up, armament, or ammunition. These words suggest the concept of being ready or armed for a situation, and have connotations of strength, power, and protection. Un-arms, on the other hand, suggests vulnerability and weakness, and implies a loss of power or defense. Therefore, using the appropriate antonym for un-arms can significantly change the meaning and tone of a sentence.