Currently not going to a water park if you do not bathe in the pool that it has or even if you go to a full day at a hotel to spend the day in the pool, but perhaps we know where this word comes from. Well the word pool comes from the Latin piscis "fish" and was originally used to designate wells for freshwater or saltwater fish. It was also used to designate the water tanks connected to the aqueducts. The first Christians used the word pool to designate the baptismal font.