The Collaborative International Dictionary of English v.0.48:

Grease \Grease\ (gr[=e]s), n. [OE. grese, grece, F. graisse;
   akin to gras fat, greasy, fr. LL. grassus thick, fat, gross,
   L. crassus. Cf. Crass.]
   1. Animal fat, as tallow or lard, especially when in a soft
      state; oily or unctuous matter of any kind.
      [1913 Webster]

   2. (Far.) An inflammation of a horse's heels, suspending the
      ordinary greasy secretion of the part, and producing
      dryness and scurfiness, followed by cracks, ulceration,
      and fungous excrescences.
      [1913 Webster]

   Grease bush. (Bot.) Same as Grease wood (below).

   Grease moth (Zool.), a pyralid moth (Aglossa pinguinalis)
      whose larva eats greasy cloth, etc.

   Grease wood (Bot.), a scraggy, stunted, and somewhat
      prickly shrub (Sarcobatus vermiculatus) of the Spinach
      family, very abundant in alkaline valleys from the upper
      Missouri to California. The name is also applied to other
      plants of the same family, as several species of
      Atriplex and Obione.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

greasewood \greasewood\ n.
   A low hardy much-branched spiny shrub (Sarcobatus
   vermiculatus) common in alkaline soils of Western America.

   Syn: black greasewood, Sarcobatus vermiculatus.
        [WordNet 1.5]

The Collaborative International Dictionary of English v.0.48:

Chico \Chi"co\, n.
   1. Var. of Chica.
      [Webster 1913 Suppl.]

   2. The common greasewood of the western United States
      (Sarcobatus vermiculatus).
      [Webster 1913 Suppl.]

   3. In the Philippines, the sapodilla or its fruit; also, the
      marmalade tree or its fruit.
      [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

Sarcobatus vermiculatus
    n 1: low hardy much-branched spiny shrub common in alkaline
         soils of western America [syn: greasewood, black
         greasewood, Sarcobatus vermiculatus]