cleft vs indentation

cleft and indentation both are nouns.

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

As nouns, indentation is a hypernym of cleft; that is, indentation is a word with a broader meaning than cleft:

Other hypernyms of cleft include indenture.

cleft (noun)	indentation (noun)
a long narrow cleft	the act of cutting into an edge with toothlike notches or angular incisions
a split or indentation in something (as the palate or chin)	the space left between the margin and the start of an indented line
	the formation of small pits in a surface as a consequence of corrosion
	a concave cut into a surface or edge (as in a coastline)

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