pirate (n.)youdaoicibaDictYouDict[pirate 词源字典]
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- (3) "to try, risk" (cognates: 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.[pirate etymology, pirate origin, 英语词源]
rhubarb (n.)youdaoicibaDictYouDict
late 14c., from Old French rubarbe, from Medieval Latin rheubarbarum, from Greek rha barbaron "foreign rhubarb," from rha "rhubarb," perhaps ultimately from a source akin to Persian rewend "rhubarb" (associated in Greek with Rha, ancient Scythian name of the River Volga) + barbaron, neuter of barbaros "foreign" (see barbarian). Grown in China and Tibet, it was imported into ancient Europe by way of Russia.

Spelling altered in Medieval Latin by association with rheum. European native species so called from 1640s. Baseball slang meaning "loud squabble on the field" is from 1938, of unknown origin, said to have been first used by broadcaster Garry Schumacher. Perhaps connected with use of rhubarb as a word repeated by stage actors to give the impression of hubbub or conversation (attested from 1934).