1296, from Anglo-Fr.
tailour, from O.Fr.
tailleor "tailor," lit. "a cutter," from
tailler "to cut," from M.L.
taliator vestium "a cutter of clothes," from L.L.
taliare "to split," from L.
talea "a slender stick, rod, staff, a cutting, twig," on the notion of a piece of a plant cut for grafting. Possible cognates include Skt.
talah "wine palm," O.Lith.
talokas "a young girl," Gk.
talis "a marriageable girl" (for sense, cf.
slip of a girl, twiggy), Etruscan
Tholna, name of the goddess of youth.
"Although historically the tailor is the cutter, in the trade the 'tailor' is the man who sews or makes up what the 'cutter' has shaped." [OED]
The verb is recorded from 1662; fig. sense of "to design (something) to suit needs" is attested from 1942.
Tailor-made first recorded 1832 (in a fig. sense); originally "heavy and plain," as of women's garments made by a tailor rather than a dress-maker.
[tey-ler] 
lər