pirate (n.) Look up pirate at Dictionary.com
c. 1300 (mid-13c. as a surname), from Latin pirata "sailor, corsair, sea robber" (source also of Spanish, Italian pirata, Dutch piraat, German Pirat), from Greek peirates "brigand, pirate," literally "one who attacks" (ships), from peiran "to attack, make a hostile attempt on, try," from peira "trial, an attempt, attack," from PIE *per-ya-, suffixed form of root *per- (3) "to try, risk," (source also of Latin experiri "to try;" Greek empeiros "experienced;" Old Irish aire "vigilance;" Gothic ferja "watcher;" Old English fær "danger, calamity"). According to Watkins, this is "A verbal root belonging to the group of" *per- (1) "forward, through" (see per) via the notion of "to lead over, to press forward."

An Old English word for it was sæsceaða. Meaning "one who takes another's work without permission" first recorded 1701; sense of "unlicensed radio broadcaster" is from 1913.
pirate (v.) Look up pirate at Dictionary.com
1570s, from pirate (n.). Related: Pirated; pirating.