Source : Webster's Revised Unabridged Dictionary (1913)

Greasy \Greas"y\, a. [Compar. {Greasier}; superl. {Greasiest}.]
   1. Composed of, or characterized by, grease; oily; unctuous;
      as, a greasy dish.

   2. Smeared or defiled with grease.

            With greasy aprons, rules, and hammers. --Shak.

   3. Like grease or oil; smooth; seemingly unctuous to the
      touch, as is mineral soapstone.

   4. Fat of body; bulky. [R.] --Shak.

   5. Gross; indelicate; indecent. [Obs.] --Marston.

   6. (Far.) Affected with the disease called {grease}; as, the
      heels of a horse. See {Grease}, n., 2.

Source : WordNet®

greasy
     adj 1: containing an unusual amount of grease or oil; "greasy
            hamburgers"; "oily fried potatoes"; "oleaginous seeds"
            [syn: {oily}, {sebaceous}, {oleaginous}]
     2: smeared or soiled with grease or oil; "greasy coveralls";
        "get rid of rubbish and oily rags" [syn: {oily}]
     [also: {greasiest}, {greasier}]