"claw of a bird of prey," late 15c., pownse, probably from Old French ponchon "lance, javelin; spine, quill" (Modern French poinçon; see punch (v.)). So called for being the "claws that punch" holes in things. In falconry, the heel claw is a talon, and others are pounces. Meaning "an act of jumping or falling upon" is from 1825. In Middle English also the name of a tool for punching holes or embossing metal (late 14c.).