The Collaborative International Dictionary of English v.0.48:

Lackey \Lack"ey\, n.; pl. Lackeys. [F. laquais; cf. Sp. & Pg.
   lacayo; of uncertain origin; perh. of German origin, and akin
   to E. lick, v.]
   An attending male servant; a footman; a servile follower.
   [1913 Webster]

         Like a Christian footboy or a gentleman's lackey.
                                                  --Shak.
   [1913 Webster]

   Lackey caterpillar (Zool.), the caterpillar, or larva, of
      any bombycid moth of the genus Clisiocampa; -- so called
      from its party-colored markings. The common European
      species (Clisiocampa neustria) is striped with blue,
      yellow, and red, with a white line on the back. The
      American species (Clisiocampa Americana and Clisiocampa
      sylvatica) are commonly called tent caterpillars. See
      Tent caterpillar, under Tent.

   Lackey moth (Zool.), the moth which produces the lackey
      caterpillar.
      [1913 Webster]