3. (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.
4. (n.) A membranous, finlike, swimming organ, as in pteropod and heteropod mollusks.
5. (n.) A finlike organ or attachment; a part of an object or product which protrudes like a fin
6. (n.) The hand.
7. (n.) A blade of whalebone.
8. (n.) A mark or ridge left on a casting at the junction of the parts of a mold.
9. (n.) The thin sheet of metal squeezed out between the collars of the rolls in the process of rolling.
10. (n.) A feather; a spline.
11. (n.) A finlike appendage, as to submarine boats.