Definition of stand pat
If you play a poker variant like 2-7 Triple Draw or Razz, stand pat is the moment when you tell everyone that you don't want to change your cards. When you make a "stand pat" and despite the fact that you have the ability to switch cards, you don't, you are very strong. Your hand is even stronger if you make a stand pat on your first turn.
Origin of the expression stand pat
The origin of the expression is not certain, but it can be traced back to the early 1900s. The expression would have been mainly used in politics. Being "stand pat" had a pejorative connotation and meant that one was reactionary and closed to new ideas and change. A "stand pat" is someone who doesn't want to change, in this case, in card poker! The expression was mostly used in the United States.