Why is the ninth month called September?
"inlet of the sea," c.1400, from Old French baie, Late Latin baia (c.640), perhaps ultimately from Iberian bahia.
"opening in a wall," late 14c. (especially bay window, early 15c.), from Old French baee "opening, hole, gulf," noun use of fem. past participle of bayer "to gape, yawn," from Medieval Latin batare "gape," perhaps of imitative origin. It is the bay in sick-bay.
"howl of a dog," early 14c., earlier "howling chorus raised (by hounds) when in contact with the hunted animal," c.1300, from Old French bayer, from PIE root *bai- echoic of howling (cf. Greek bauzein, Latin baubari "to bark," English bow-wow; cf. also bawl). From the hunting usage comes the transferred sense of "final encounter," and thence, on the notion of putting up an effective defense, at bay.
laurel shrub (Laurus nobilis, source of the bay leaf), late 14c., originally only of the berry, from Old French baie (12c.) "berry, seed," from Latin baca "berry." Extension to the shrub itself is from 1520s. The leaves or sprigs were woven as wreaths for conquerors or poets. Bayberry first recorded 1570s, after the original sense had shifted.
"reddish-brown," usually of horses, mid-14c., from Anglo-French bai (13c.), Old French bai, from Latin badius "chestnut-brown" (used only of horses), from PIE *badyo- "yellow, brown" (cf. Old Irish buide "yellow"). Also elliptical for a horse of this color.
"to bark or howl (at)," late 14c., from bay (n.3). Related: Bayed; baying.
denotes the estuary of the Dead Sea at the mouth of the Jordan (Josh. 15:5; 18:19), also the southern extremity of the same sea (15:2). The same Hebrew word is rendered "tongue" in Isa. 11:15, where it is used with reference to the forked mouths of the Nile. Bay in Zech. 6:3, 7 denotes the colour of horses, but the original Hebrew means strong, and is here used rather to describe the horses as fleet or spirited.