There are numerous synonyms for the phrase "having a part in." One such synonym is "contributing." This implies that the person or thing in question is actively and positively adding to a situation or outcome. Another synonym is "participating," which emphasizes the idea of taking an active role in something. "Involvement" is another synonym, indicating that the person or thing is engaged in a particular activity or situation. "Engagement" and "partaken" also convey a similar meaning. All these synonyms have a positive connotation, emphasizing the importance of active participation and contribution to success. Overall, these synonyms provide a variety of effective ways to describe the act of having a part in something.