Impingent is a word that is used to describe something that has an impact or a forceful effect. Some synonyms for impingent include influential, powerful, impactful, significant, and dominant. These words all refer to something that has a strong effect on a situation or outcome. Other synonyms for impingent might include striking, compelling, and compelling. These words all suggest a sense of urgency or importance in the impact of something. Impingent can also be used to describe something that is invasive or intrusive, such as an impingent object that is causing discomfort or harm. In this context, synonyms might include invasive, intrusive, encroaching, or insidious.