Source : Webster's Revised Unabridged Dictionary (1913)

Outcrop \Out"crop`\, n. (Geol.)
   (a) The coming out of a stratum to the surface of the ground.
       --Lyell.
   (b) That part of inclined strata which appears at the
       surface; basset.

Outcrop \Out*crop"\, v. i. (Geol.)
   To come out to the surface of the ground; -- said of strata.

Source : WordNet®

outcrop
     n : the part of a rock formation that appears above the surface
         of the surrounding land [syn: {outcropping}, {rock
         outcrop}]
     [also: {outcropping}, {outcropped}]

outcrop
     v : appear on the surface, come to the surface on the ground;
         "Big boulders outcropped"
     [also: {outcropping}, {outcropped}]