Other forms: shared, shares, sharing
To share is to let other people have part of what is yours — food, a room, a taxi, an opinion. Share a flat, share the news, share a bag of crisps.
The internet has given the word an enormous second life: to share a post, a photo, a link, and share is now the standard label on the button. That sense means to make public rather than to divide, which is almost the opposite of the original, and both live side by side. The noun is a share of something, meaning the part that is yours, and in finance shares are units of ownership in a company. Note share with a person and share among a group.
Too few real examples of this word to estimate which sense is commonest.
share is a way of dividing or giving.
Old English scearu meant a cutting or a division, from a root meaning to cut — the same root as shear, score and short. To share was to cut something into parts, and the modern warm sense of sharing is a long way from that knife.
Middle English
schare
English, today
share
From Middle English schare. From Middle English schare, schere, from Old English sċearu (“a cutting, shaving, a shearing, tonsure, part, division, share”), from Proto-West Germanic skaru, from Proto-Germanic skarō (“a division, detachment”), from Proto-Indo-European (s)ker- (“to cut, divide”). Cognate with stq skar, sker (“a share in a communal pasture”), Dutch schare (“share in property”), German Schar (“band, troop, party, company”), Icelandic skor (“department”). Compare shard, shear. a doublet of eschel.
Etymology from Wiktionary, CC BY-SA