cleft vs volcano

cleft and volcano both are nouns.

Word	Noun	Adjective	Verb	Adverb
cleft	Yes	Yes	No	No
volcano	Yes	No	No	No

As nouns, volcano is a hyponym of cleft; that is, volcano is a word with a more specific, narrower meaning than cleft:

cleft: a long narrow cleft
volcano: a fissure in the earth's crust (or in the surface of some other planet) through which molten lava and gases erupt

cleft (noun)	volcano (noun)
a long narrow cleft	a mountain formed by volcanic material
a split or indentation in something (as the palate or chin)	a fissure in the earth's crust (or in the surface of some other planet) through which molten lava and gases erupt

cleft (adjective)	volcano (adjective)
having one or more indentations reaching nearly to the midrib
split or divided