a person who attacks and robs ships at sea

in the three weeks leading up to the attack, sixteen container ships had been boarded by pirates

a pirate ship

a person who appropriates or reproduces the work of another for profit without permission, usually in contravention of patent or copyright

software pirates

pirate recordings

a person or organization that broadcasts radio or television programmes without official authorization

a pirate radio station

use or reproduce (another's work) for profit without permission, usually in contravention of patent or copyright

his latest album has been pirated and downloaded so many times since its release that he's lost $10 million in sales

the company is seeking compensation from people who pirated the movie

rob or plunder (a ship)

nine ships were pirated off the coast of the country between 2006 and May of last year