lappet \lap"pet\, n. dim. of lap a fold.
   a small decorative fold or flap, esp. of lace or muslin, in a
   garment or headdress. --swift.
   1913 webster

   lappet moth zool., one of several species of bombycid
      moths, which have stout, hairy caterpillars, flat beneath.
      two common american species gastropacha americana, and
      tolype velleda feed upon the apple tree.
      1913 webster
see also:
lappet moth gastropacha americana tolype velleda