braid (v.)youdaoicibaDictYouDict[braid 词源字典]
"to plait, knit, weave, twist together," c. 1200, breidan, from Old English bregdan "to 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 *bregthan "make sudden jerky movements from side to side" (compare Old Norse bregða "to brandish, turn about, braid;" Old Saxon bregdan "to weave;" Dutch breien "to knit;" Old High German brettan "to draw, weave, braid"), from PIE root *bherek- "to gleam, flash" (compare Sanskrit bhrasate "flames, blazes, shines"). In English the verb survives only in the narrow definition of "plait hair." Related: Braided; braiding.[braid etymology, braid origin, 英语词源]
door (n.)youdaoicibaDictYouDict
Middle English merger of Old English dor (neuter; plural doru) "large door, gate," and Old English duru (fem., plural dura) "door, gate, wicket;" both from Proto-Germanic *dur- (cognates: Old Saxon duru, Old Norse dyrr, Danish dør, Old Frisian dure, Old High German turi, German Tür).

The Germanic words are from PIE *dhwer- "a doorway, a door, a gate" (cognates: Greek thyra, Latin foris, Gaulish doro "mouth," Gothic dauro "gate," Sanskrit dvárah "door, gate," Old Persian duvara- "door," Old Prussian dwaris "gate," Russian dver' "a door").

The base form is frequently in dual or plural, leading to speculation that houses of the original Indo-Europeans had doors with two swinging halves. Middle English had both dure and dor; form dore predominated by 16c., but was supplanted by door.
A door is what a dog is perpetually on the wrong side of. [Ogden Nash]