Retro-action is often used to describe an action that is taken in response to a previous action. However, there are several synonyms that can be used to convey this same meaning. For instance, the word "counteraction" can be used to describe an action taken in response to another action. Similarly, the word "retribution" can be used to describe a response that is meant to be corrective or punishing. The word "backlash" can also be used to describe a forceful response to an action that is seen as unfavorable. Other synonyms for retro-action include "reaction," "reprisal," and "retaliation," all of which convey the idea of a response to a previous action.