Why is the ninth month called September?
"large scissors," Old English scearra (plural) "shears, scissors," from Proto-Germanic *sker- "to cut" (cf. Middle Dutch schaer, Old High German scara, German Schere; see shear (v.)). In 17c., also "a device for raising the masts of ships" (1620s). As "scissors," OED labels it Scottish and dialectal. Chalk is no shears (1640s) was noted as a Scottish proverb expressing the gap between planning and doing.
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" (cf. Old Norse and Old Frisian skera, Dutch scheren, German scheren "to shear"), from PIE *(s)ker- (1) "to cut, to scrape, to hack" (cf. 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").
"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.