Co action is defined as the act of working together towards a common goal. The antonyms for co action are words that describe the opposite behavior. The first antonym for co action is isolation. Isolation is the act of being alone and disconnected from others, therefore, it is the opposite of working together. The next antonym is competition which refers to people focusing on individual goals at the expense of others. Another antonym for co action is obstruction which means to hinder or prevent progress. Lastly, there is resistance which is when people work against each other rather than working together. In conclusion, the antonyms for co action describe behaviors that hinder or prevent progress and success.