c. 1300, "to fasten (a gate, etc.) with a bar," from bar (n.1); sense of "to obstruct, prevent" is recorded by 1570s. Expression bar none "without exception" is recorded from 1866.
"tavern," 1590s, so called in reference to the bars of the barrier or counter over which drinks or food were served to customers (see bar (n.1)).
unit of pressure, coined 1903 from Greek baros "weight," which is related to barys "heavy" (from PIE root *gwere- (1) "heavy").
c. 1300, snak, "to bite or snap" (of a dog), perhaps from a Northern variant of snatch (v.) influenced by Scandinavian words (such as Old Norse snakka); or perhaps also from or influenced by continental Germanic words such as Middle Dutch snakken, Flemish snacken "to snatch, snap; chatter," which Watkins traces to a hypothetical Germanic imitative root *snu- forming words having to do with the nose (see snout).
The meaning "have a mere bite or morsel, eat a light meal" is attested by 1807. Related: Snacked; snacking.
c. 1400, snak, "a snatch or snap" (especially that of a dog), from snack (v.). Later "a snappish remark" (1550s); "a share, portion, part" (1680s; hence old expressions such as go snacks "share, divide; have a share in").
The meaning "a bite or morsel to eat hastily" is attested from 1757. Snack bar "counter from which snacks are served" is attested from 1923. The unetymological commercial plural snax is attested from 1942 in the vending machine trade.
late 12c., "stake or rod of iron used to fasten a door or gate," from Old French barre "beam, bar, gate, barrier" (12c.), from Vulgar Latin *barra "bar, barrier," which some suggest is from Gaulish *barros "the bushy end" [Gamillscheg, etc.], but OED regards this as "discredited" because it "in no way suits the sense." Welsh bar "a bar, rail," Irish barra "a bar, spike" are said to be from English; German Barre, Danish barre, Russian barŭ are from Medieval Latin or Romanic.
The general sense of "anything which obstructs, hinders, or impedes" is from 1530s. Of soap, by 1833; of candy, by 1906 (the process itself dates to the 1840s), both from resemblance of shape. The meaning "bank of sand across a harbor or river mouth" is from 1580s, probably so called because it was an obstruction to navigation.
Bar graph is attested from 1925. Bar code first recorded 1963. Behind bars "in prison" is attested by 1934, American English.
"whole body of lawyers, the legal profession," 1550s, a sense which derives ultimately from the railing that separated benchers from the hall in the Inns of Court (see bar (n.1)). Students who had attained a certain standing were "called" to it to take part in the important exercises of the house. After c. 1600, however, this was popularly assumed to mean the bar in a courtroom, the wooden railing marking off the area around the judge's seat, where prisoners stood for arraignment and where a barrister (q.v.) stood to plead. As the place where the business of court was done, bar in this sense had become synonymous with court by early 14c.
1842, in Judaism, "male person who has completed his 13th year" and thus reached the age of religious responsibility; Hebrew, literally "son of command." As a name for the ceremony itself, by 1917.
1725, "the need very badly to urinate," from Latin micturitum, from past participle of micturire "to desire to urinate," desiderative of mingere "to urinate," from PIE root *meigh- "to urinate." As during the final 20 minutes of a 4-hour film after drinking a 32-ounce Mountain Dew from the snack bar and the movie ends with a drawn-out farewell scene while Frodo is standing on the pier and wavelets lap audibly on the dock the whole time as if the director was a sadist set on compounding your torment. Also used, incorrectly, for "act of urinating."