Nonformal agreement refers to a mutual understanding or arrangement between two or more parties without the use of legal or formal documents. There are several synonyms for this term, including informal agreement, verbal agreement, handshake agreement, and gentleman's agreement. These phrases imply a level of trust and mutual respect between the parties involved, but also suggest a lack of legal protection or enforcement. Other synonyms could include pact, deal, arrangement, or contract-in-progress. It is important to note that nonformal agreements may still hold weight and be upheld in certain circumstances, but they should not be relied upon as the sole means of establishing a business or personal relationship.