An agreement generally between two males or occasionaly two parties (I.E countries) in which an informal agreement is made as apposed to something that is signed and ratified and usually has no legal basis, it is simply a man giving his word that he will do something which is based on the traditional value of honour amongst gentlemen. That should one man break his end of the agreement his Honour and trustworthiness will be called into repute and his status as a gentleman is finished. More modern language is likely used such as "losing your man card" for breaches of the agreement but the principle stays the same.

Has been used many times in the past particularly during war amongst generals (who were considered men of honour) to broker such things as temporary ceasefires to evacuate wounded men, or the famous Christmas truce in WW1.

A more modern and simpler example would be if two guys were watching a sports game and they decided to bet each other on the outcome. The agreement is informal but there is a gentlemans agreement to follow through and pay up should one lose. Failure to pay on losing would be a breach of the gentlemans agreement and the loser runs the risk of being known as a bad payer and people would be less likely to bet with him in the future thus tarnishing his reputation and his word
The Christmas truce of 1914 was a prime example of a gentlemans agreement. That each man would lay his weapons down for the sake of the unofficial ceasefire, with each man effectively upholding a gentlemans agreement that they would not attack
by ArkadyVasiliev June 5, 2017
Get the Gentlemans Agreement mug.
An unwritten agreement between a group of people (usually friends playing a game) to not do something extremely dickish or unfair, no matter how tempting or obvious it may be.
A famous example of a gentleman's agreement is when players would always agree to not use Oddjob in Goldeneye N64, and no one would object.
by Someone who kinda exists September 6, 2022
Get the Gentleman's Agreement mug.
John yesterday hit Elis in his Gentleman's agreement. It hurt Elis.
by Llusnewo November 24, 2020
Get the Gentleman's agreement mug.
An agreement set in place between the gentlemen of the second floor. This agreements calls for no dookage within the east bathroom of said floor.
The gentlemans agreement must be called when the catcher is calling for a duece. This is for the greater good of the second floor.

"Hey Brian, you taking a shit AGAIN"

"If you break the gentlemans agreement again you WILL eat your own shit."
by big balls May 6, 2005
Get the gentlemans agreement mug.
an agreement between 2 guys to have no strings attached and be physical; aka: a gay fuck buddy
when your in a gay bar and you go up to a man saying, "would u like to exchange in a gentleman's agreement?"
by goodtimewaiting April 26, 2010
Get the gentleman's agreement mug.
When the gang you are currently beating the shit out of always waits for you to finish this one guy before another person in the gang goes after you.
Gentleman's Agreement is a lousy thing to do in movies... It's a shame.
by DesiredExoticNeighbor June 22, 2018
Get the Gentleman's Agreement mug.