cliffhanger vs installment

cliffhanger and installment both are nouns.

Word	Noun	Adjective	Verb	Adverb
cliffhanger	Yes	No	No	No
installment	Yes	No	No	No

As nouns, installment is a hypernym of cliffhanger; that is, installment is a word with a broader meaning than cliffhanger:

Other hypernyms of cliffhanger include episode, instalment.

cliffhanger (noun)	installment (noun)
an episode that ends in suspense	the act of installing something (as equipment)
a contest whose outcome is uncertain up to the very end	a part of a broadcast serial
	a part of a published serial
	a payment of part of a debt; usually paid at regular intervals