shearyoudaoicibaDictYouDict[shear 词源字典]
shear: [OE] Shear is the principal English descendant of the Indo-European base *sker- ‘cut’, which has also produced English score, share, shirt, short, and skirt, and probably sharp and shore as well. A variant of the base without the s is responsible for curt and curtail. The immediate source of shear itself is prehistoric Germanic *skeran, which also evolved into German and Dutch scheren, Swedish skära, and Danish skjære.

The verb sheer ‘swerve’ [17] probably originated as a variant of shear, but the adjective sheer [16] is an entirely different word. It probably represents a survival of Old English scīr ‘bright, shining’, which came ultimately from the Germanic base *ski-, source also of English shimmer and shine.
=> curt, curtail, score, share, sheer, shirt, short, skirt[shear etymology, shear origin, 英语词源]
shear (v.)youdaoicibaDictYouDict
Old English sceran, scieran (class IV strong verb; past tense scear, past participle scoren) "to cleave, hew, cut with a sharp instrument; cut (hair); shear (sheep)," from Proto-Germanic *sker- "to cut" (cognates: Old Norse and Old Frisian skera, Dutch scheren, German scheren "to shear"), from PIE *(s)ker- (1) "to cut, to scrape, to hack" (cognates: Sanskrit krnati "hurts, wounds, kills," krntati "cuts;" Hittite karsh- "to cut off;" Greek keirein "to cut, shear;" Latin curtus "short;" Lithuanian skiriu "to separate;" Old Irish scaraim "I separate;" Welsh ysgar "to separate," ysgyr "fragment").
shear (n.)youdaoicibaDictYouDict
"act of clipping," 1610s, also as a unit of measure of the age of a sheep, from shear (v.). Scientific and mechanical sense "type of strain" is from 1850.