Fish is a term reserved for the poker table, and it is often used to refer to the players who tend to lose often and bet on virtually every hand. While the term is most often used around poker tables, it is also used in everyday life, and it was coined as the opposite of the term shark.
When it comes to the poker table, in particular, players refer to the most experienced players at the table as sharks while they refer to the most inexperienced ones as fish the sharks prey on. In other words, sharks tend to play the hands that fish do and make a profit by taking advantage of their inexperience.
Did you know that experienced poker players coined the phrase If you are unable to spot the fish at a casino table, then you are the fish? Remembering this might save you some cash and help you swim out of the shark-infested waters!