Match the pot

To match the pot is to bet the same amount as is currently in the pot. Technically, this is the maximum allowed bet in a pot-limit game, though in such games it is rarely called "match the pot" and is more commonly called "bet the pot" or just "pot" for short.

Matching the pot is usually used to describe a forced bet of the size of the pot, which is only found in unusual variants of poker where the rules state that a player must be "penalized" for some action or inaction, and the penalty is to bet a large amount that equals the pot size. Clearly, this type of "penalty" gets worse as the pot gets bigger.