(n.) An organ of a fish, consisting of a membrane supported by rays, or little bony or cartilaginous ossicles, and serving to balance and propel it in the water.
(n.) A membranous, finlike, swimming organ, as in pteropod and heteropod mollusks.
(n.) A finlike organ or attachment; a part of an object or product which protrudes like a fin
(n.) The hand.
(n.) A blade of whalebone.
(n.) A mark or ridge left on a casting at the junction of the parts of a mold.
(n.) The thin sheet of metal squeezed out between the collars of the rolls in the process of rolling.