"large scissors," Old English scearra (plural) "shears, scissors," from Proto-Germanic *sker- "to cut" (cognates: 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.
