1. robber at sea: a robber who operates from a ship on the ocean
2. ship used by sea robbers: a ship used by people who rob or otherwise attack shipping on the high seas
3. somebody using copyrighted material without permission: somebody who duplicates or uses copyrighted or patented material illegally or without authorization
4. somebody involved in illegal broadcasting: somebody who takes part in or manages the unauthorized or illegal broadcasting of TV or radio programs
verb (past and past participlepi·rat·ed, present participlepi·rat·ing, 3rd person present singularpi·rates)
Definition:
1. transitive and intransitive verb rob something on high seas: to rob a vessel or commit robbery on the high seas
2. transitive verb use copyrighted material without permission: to duplicate or use copyrighted or patented material without authorization or without the legal right to do so
[13th century. Via Latin pirata< Greek peiratēs< peiran "to attack"]