Co-adjutants are individuals who assist others in carrying out tasks. The antonyms for this word would be those that imply hindrance or obstruction. Words like adversary, antagonist, impediment, and hindrance would be appropriate antonyms. An adversary is someone who opposes or fights against something or someone, while an antagonist is someone who actively opposes someone or something. Impediments and hindrances both refer to obstacles that get in the way of progress or forward movement. These antonyms are useful for expressing the opposite of cooperation and assistance, highlighting a tension or conflict between individuals or groups.