a gentleman's agreement
a gentleman's agreementor
a gentlemen's agreement
A gentleman's agreement or a gentlemen's agreement is an informal agreement that is not written down but in which people trust one another to do what they have promised. We had no contract; it was done by a gentleman's agreement. I'm hoping we can come to a gentlemen's agreement, Colonel.
a gentleman's agreementan arrangement or understanding which is based on the trust of both or all parties, rather than being legally binding.
1991 Charles Anderson Grain: Entrepreneurs There had been a ‘gentleman's agreement’ by the Grain Growers not to enter the markets of Saskatchewan Wheat Pool's predecessor.