A more thorough explanation:

Definition: A promissor is a party in civil law who undertakes to do something in response to the request of another party, known as the stipulator.

For example, if John promises to pay Jane $100 for completing a task, John is the promissor and Jane is the stipulator.

Other related terms include:

• Promissory: Containing or consisting of a promise. For instance, a promissory note is a written promise to pay a specific amount of money.
• Promissory condition: A condition in a contract that requires one party to perform an action before the other party is obligated to fulfill their promise.
• Promissory estoppel: A legal principle that prevents a promissor from going back on their promise if the other party relied on that promise to their detriment.
• Promissory fraud: A type of fraud where a promissor makes a false promise with the intent to deceive the other party.
• Promissory oath: An oath that promises to do something in the future.
• Promissory representation: A statement made by a promissor that they will do something in the future.
• Promissory restraint: A clause in a contract that attempts to discourage a later conveyance by imposing contractual liability on anyone who makes a later conveyance.