c.1300 (mid-13c. as a surname), from Latin pirata "sailor, corsair, sea robber" (source of Spanish, Italian pirata, Dutch piraat, German Pirat), literally "one who attacks (ships)," from Greek peirates "brigand, pirate," literally "one who attacks," from peiran "to attack, make a hostile attempt on, try," from peira "trial, an attempt, attack," from PIE root *per- "try" (cf. Latin peritus "experienced," periculum "trial, experiment; attempt on or against; enterprise;" see peril). 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.
1570s, from pirate (n.). Related: Pirated; pirating.