A subordinate event is one that is of lesser importance or significance compared to the primary event. Synonyms for subordinate event could include secondary event, minor event, incidental event, auxiliary event, supporting event, supplementary event, additional event, and collateral event. These terms all imply that the event is less important or serves as a complement to the primary event. Using synonyms for subordinate event can help clarify the level of importance or relevance of the event being discussed. It can also aid in effectively communicating the hierarchy of events in a given situation, allowing for more clarity and understanding among all parties involved.