late 14c., "group of people, animals, etc.; kind or variety of person or animal," from Old French sorte "class, kind," from Latin sortem (nominative sors) "lot; fate, destiny; share, portion; rank, category; sex, class, oracular response, prophecy," from PIE root *ser- (2) "to line up."
The sense evolution in Vulgar Latin is from "what is allotted to one by fate," to "fortune, condition," to "rank, class, order." Later (mid-15c.) "group, class, or category of items; kind or variety of thing; pattern, design." Out of sorts "not in usual good condition" is attested from 1620s, with literal sense of "out of stock."
c. 1300, "witchcraft, magic, enchantment; act or instance of sorcery; supernatural state of affairs; seemingly magical works," from Old French sorcerie, from sorcier "sorcerer, wizard," from Medieval Latin sortiarius "teller of fortunes by lot; sorcerer," literally "one who influences fate or fortune," from Latin sors (genitive sortis) "lot, fate, fortune" (see sort (n.)).
Proto-Indo-European root meaning "to line up."
It forms all or part of: assert; assertion; assort; consort; desert (v.) "to leave one's duty;" desertion; dissertation; ensorcell; exert; exsert; insert; seriatim; seriation; series; sermon; serried; sorcerer; sorcery; sort.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit sarat- "thread;" Greek eirein "to fasten together in rows;" Latin serere "to join, link, bind together," series "row, chain, series, sequence, succession;" Gothic sarwa (plural) "armor, arms;" Old Norse sörve "necklace of stringed pearls;" Old Irish sernaid "he joins together;" Welsh ystret "a row."