bridle n.

"plait, knit, weave, twist together," c. 1200, breidan, from Old English bregdan "move quickly, pull, shake, swing, throw (in wrestling), draw (a sword); bend, weave, knit, join together; change color, vary; scheme, feign, pretend" (class III strong verb, past tense brægd, past participle brogden), from Proto-Germanic *bregdanan "make sudden jerky movements from side to side" (compare Old Norse bregða "brandish, turn about, move quickly; braid;" Old Saxon bregdan "weave, braid;" Old Frisian brida "twitch (the eye);" Dutch breien "knit;" Old High German brettan "draw, weave, braid"), perhaps from a PIE root *bhrek- (compare Sanskrit bhurati "moves quickly," Lithuanian bruzdùs "fast"), but there are phonetic difficulties. In English the verb survives only in the narrow definition of "plait hair." Related: Braided; braiding.

late 14c., originally in figurative sense of "unrestrained, ungoverned," from un- (1) "not" + bridled (see bridle (v.)). Similar formation in Middle Dutch ongebreidelt. Literal sense of "not fitted with a bridle" (of horses) is not recorded before 1550s. The verb unbridle (see un- (2)) is attested from c. 1400 in the literal sense; mid-15c. in the figurative sense.

"removal of damaged tissue from a wound," 1839, from French débridement, literally "an unbridling," from débrider "to unbridle," from dé- (see de-) + bride "bridle," from a Germanic source akin to Middle High German bridel (see bridle (n.)). Related: debride, debriding.