(archaic or loosely) Any animal (or any vertebrate) that lives exclusively in water.
(uncountable) The flesh of the fish used as food.
(uncountable) A cardgame in which the object is to obtain cards in pairs or sets of four (depending on the variation), by asking the other players for cards of a particular rank.
(poker) A bad poker player. Compare shark (a good poker player).
(countable, nautical) A makeshiftoverlapping longitudinal brace, originally shaped roughly like a fish, used to temporarily repair or extend a spar or mast of a ship.