Wiktionary
vb. 1 (context geology intransitive English) To appear above the surface, as a seam or vein, or inclined bed, as of coal. 2 (context intransitive English) To come to light; to be manifest; to appear.
WordNet
v. appear at the surface; "A seam of coal bassets" [syn: basset]
Usage examples of "crop out".
He has been dragging a crop out of it in this way and that for twenty years and not a bit has he put back of manure or bean cake.
Let it wash a man's crop out of the ground year after year, and them up there in Washington spending fifty thousand dollars a day keeping an army in Nicarauga or some place.
He plucked the riding crop out of his boot and slapped fitfully at his calf with it.
And I guess if a person is willing to do a thing like that, then he's stupid to begin with and it's bound to crop out on him sooner or later.