'Share' is PIE *sker- (to cut) — sharing was cutting something whole into portions for distribution.
To give a portion of something to others; to use, occupy, or enjoy something jointly.
From Old English 'scearu' (a cutting, division, a part allotted, a share), from Proto-Germanic *skarō (a cutting, division), from PIE *sker- (to cut). The verb developed from the noun in Middle English — to share was to cut something into portions and distribute it. The same root produced 'shear,' 'scar,' 'score,' and
A 'ploughshare' — the cutting blade of a plough — contains 'share' in its original sense: a cutting instrument. The biblical phrase 'beat swords into ploughshares' thus pairs two cutting tools, one for destruction and one for cultivation. Both 'share' (the blade) and 'share' (a portion