means A person whose trade is making, altering, and fitting clothing — especially fitted garments like suits and jackets — to an individual's measurements.

from From Old French 'tailleor,' a cutter, from the verb 'tailler,' to cut — which itself traces back to Late Latin 'taliare,' to split or cut, from 'talea,' a slender stick or cutting (the same root that gives us 'detail' and 'retail'). At heart, then, a tailor is simply 'one who cuts' — the craft named not for the sewing but for that first decisive scissor-stroke into the cloth.