"close growth of hair on the chin and lower face, normally characteristic of an adult male" (that of the upper lip being distinguished in Modern English as the mustache), Old English beard "beard," from Proto-Germanic *bard (source also of Old Frisian berd, Middle Dutch baert, Old High German bart, German bart), said in Pokorny to be from a PIE root *bhardhā- "beard" (source also of Old Church Slavonic brada, Russia boroda, Lithuanian barzda, Old Prussian bordus, and perhaps Latin barba "beard"), but Boutkan rejects this on phonetic grounds and suggests a non-IE substrate word. Old French berd is from Germanic.
The Greek and Roman Churches have long disputed about the beard. While the Romanists have at different times practised shaving, the Greeks, on the contrary, have strenuously defended the cause of long beards. Leo III. (795 AD) was the first shaved Pope. Pope Gregory IV., after the lapse of only 30 years, fulminated a Bull against bearded priests. In the 12th century the prescription of the beard was extended to the laity. Pope Honorius III. to disguise his disfigured lip, allowed his beard to grow. Henry I. of England was so much moved by a sermon directed against his beard that he resigned it to the barber. Frederick Barbarossa is said to have been equally tractable. [Tom Robinson, M.D., "Beards," St. James's Magazine, 1881]
Pubic hair sense is from 1600s (but neþir berd "pubic hair" is from late 14c.); in the 1811 "Dictionary of the Vulgar Tongue," the phrase beard-splitter is defined as, "A man much given to wenching" (compare beaver in the slang genital sense).
medieval weapon (a broad blade with sharp edges, ending in a point and mounted on a long handle), late 15c., from French hallebarde (earlier alabarde, 15c.), from Middle High German halmbarte "broad-axe with handle," from halm "handle" (see helm) + barte "hatchet," from Proto-Germanic *bardoz "beard" (see beard (n.)), also "hatchet, broadax" ("because the actual axe looks like a beard stuck to the wooden handle" - Boutkan). An alternative etymology [Kluge, Darmesteter] traces first element to helm "helmet," making the weapon an axe for smashing helmets. In 15c.-16c. especially the arm of foot-soldiers.
"repellent, unattractive," 1885, from French rébarbatif (14c.), from barbe "beard," from Latin barba (see barb (n.)). The usual theory is that it refers to the itchy, irritating quality of a beard.
late 14c., "barb of an arrow," from Old French barbe "beard, beard-like appendage" (11c.), from Latin barba "beard," from Proto-Italic *farfa- "beard," which might be from a common PIE root *bhardhā- "beard" (source also of Old Church Slavonic brada, Russia boroda, Lithuanian barzda, Old Prussian bordus), but according to De Vaan the vowel "rather points to a non-IE borrowing into the European languages."