Origin: 1325–75; ME < L subtīlis fine (orig. of fabric), equiv. to sub-sub-+ -tīlis, akin to tēla cloth on a loom, loom (< *tekslā, deriv. of texere to weave; see text)
[Middle English, from Old French subtil, from Latin subtīlis, fine, delicate; see subtle.] sub'tile·ly adv., sub·til'i·ty (səb-tĭl'ĭ-tē), sub'tile·ness (sŭt'l-nĭs, sŭb'təl-), sub'til·ty (sŭt'l-tē, sŭb'təl-) n.
c.1374, "clever, dexterous," from O.Fr. subtil (14c.), from L. subtilis "fine, thin, delicate" (see subtle). A Latinized refashioning of the O.Fr. source of subtle.