Upon even terms means a situation where two or more parties have an equal footing or equal advantage in a particular situation. Some synonyms for upon even terms include equal footing, level playing field, equal advantage, parity, and even keel. When two parties are upon even terms, there is no advantage to either party and both parties have an equal opportunity to succeed. This term is often used in legal, business, or sports situations where fairness and equality are essential. Therefore, having a thorough understanding of synonyms for upon even terms can help improve communication in such situations.