<p><strong>Noun</strong></p><ul><li>a person who robs or commits illegal violence at sea or on the shores of the sea.</li><li>Synonyms: plunderer, corsair, buccaneer, freebooter.</li><li>a ship used by such persons.</li><li>any plunderer, predator, etc.: confidence men, slumlords, and other pirates.</li><li>a person who uses or reproduces the work or invention of another without authorization.</li><li>Also called pirate stream.</li><li>Geology: a stream that diverts into its own flow the headwaters of another stream, river, etc.</li></ul><p><strong>Verb</strong></p><ul><li>(used with object) pirated, pirating: to commit piracy upon; plunder; rob.</li><li>to take by piracy: to pirate gold.</li><li>to use or reproduce (a book, an invention, etc.) without authorization or legal right: to pirate hit records.</li><li>to take or entice away for one's own use: Our competitor is trying to pirate our best salesman.</li><li>(used without object) pirated, pirating: to commit or practice piracy.</li></ul>