Moonfish \Moon"fish`\, n. (Zo["o]l.) (a) An American marine fish ({Vomer setipennis}); -- called also {bluntnosed shiner}, {horsefish}, and {sunfish}. (b) A broad, thin, silvery marine fish ({Selene vomer}); -- called also {lookdown}, and {silver moonfish}. (c) The mola. See {Sunfish}, 1.