"portion," O.E. scearu "a cutting, shearing, division," related to sceran "to cut," from P.Gmc. *skaro- (cf. O.H.G. scara "troop, share of forced labor," Ger. Schar "troop, band," prop. "a part of an army," O.N. skör "rim"), from PIE base *sker- "to cut" (see shear). Meaning "part of the capital of a joint stock company" is first attested 1601. Shareholder first attested 1828. To share-crop is first recorded 1867.
"iron blade of a plow," O.E. scear, scær "plowshare," prop. "that which cuts," from P.Gmc. *skar- (cf. O.Fris. skere, M.L.G. schar, O.H.G. scar, Ger. Schar, Du. ploegschaar, M.H.G. pfluocschar), from PIE base *(s)ker- "to cut" (see shear).