means the craft of cutting and sewing garments to fit a particular body or purpose, especially the precise shaping of suits, jackets, and coats.

from From 'tailor,' which English borrowed from the Anglo-Norman 'taillour,' itself from Old French 'tailleor' — one who cuts. The deeper root is the Latin verb 'taliare,' to cut or split, a cousin of 'tally' and 'detail.' So at heart a tailor is simply a cutter: the whole art begins with the shears, and the word remembers it.