indentation vs cleft

indentation and cleft both are nouns.

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

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

Other hyponyms of indentation include notch, notch.

indentation (noun)	cleft (noun)
the act of cutting into an edge with toothlike notches or angular incisions	a long narrow cleft
the space left between the margin and the start of an indented line	a split or indentation in something (as the palate or chin)
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)

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