outthrust vs outcropping

outthrust and outcropping both are nouns.

Word	Noun	Adjective	Verb	Adverb
outthrust	Yes	No	No	No
outcropping	Yes	No	No	No

As nouns, outcropping is a hypernym of outthrust; that is, outcropping is a word with a broader meaning than outthrust:

outthrust: an outcropping of rock that extends outward
outcropping: the part of a rock formation that appears above the surface of the surrounding land

Other hypernyms of outthrust include outcrop, rock outcrop.

outthrust (noun)	outcropping (noun)
an outcropping of rock that extends outward	the part of a rock formation that appears above the surface of the surrounding land