/puy"reuh see/ , n. , pl. piracies .
1. practice of a pirate; robbery or illegal violence at sea.
2. the unauthorized reproduction or use of a copyrighted book, recording, television program, patented invention, trademarked product, etc.: The record industry is beset with piracy.
3. Also called stream capture . Geol. diversion of the upper part of one stream by the headward growth of another.
[ 1545-55; earlier pyracie piratia peirateía. See PIRATE, -ACY ]