subtle Look up subtle at Dictionary.com
c.1300, sutel, soutil, in ref. to things, "of thin consistency;" in ref. to craftsmen, "skilled, clever," from O.Fr. soutil, from L. subtilis "fine, thin, delicate, finely woven," from sub "under" + -tilis, from tela "web" and texere "to weave" (see texture). The spelling with -b- reflects confusion with subtile. Most non-material senses were present by late 14c.