c. 1400, "engage in business transactions, discuss or arrange terms of a transaction; to vend or sell," from Old French bargaignier "to haggle over the price" (12c., Modern French barguigner), perhaps from Frankish *borganjan "to lend" or some other Germanic source, ultimately from Proto-Germanic *borgan "to pledge, lend, borrow" (source also of Old High German borgen; Old English borgian; from PIE root *bhergh- (1) "to hide, protect;" compare borrow).
Diez and others suggest that the French word comes from Late Latin barca "a barge," because it "carries goods to and fro." There are difficulties with both suggestions. Related: Bargained; bargaining. To bargain for "arrange for beforehand" is from 1801.
c. 1600, "male voice between tenor and bass," from Italian baritono, from Greek barytonos "deep-toned, deep-sounding," from barys "heavy, deep," also, of sound, "strong, deep, bass" (from PIE root *gwere- (1) "heavy") + tonos "tone," from PIE root *ten- "to stretch."
Technically, "ranging from lower A in bass clef to lower F in treble clef." Meaning "singer having a baritone voice" is from 1821. As a type of brass band instrument, it is attested from 1949. As an adjective, 1729 in reference to the voice, 1854 of musical instruments (originally the concertina).
1808, coined in Modern Latin by its discoverer, English chemist Sir Humphry Davy, because it was present in the mineral barytes "heavy spar" (barium sulphate), so named by Lavoisier from Greek barys "heavy," from PIE root *gwere- (1) "heavy." The metal is actually relatively light. With chemical ending -ium. Related: Baric.
"any small vessel or ship," early 15c., from French barque "boat" (15c.), from Late Latin barca, which is probably cognate with Vulgar Latin *barica (see barge (n.)). More precise sense of "three-masted ship fore-and-aft rigged on the mizzenmast" (17c.) often is spelled barque to distinguish it.