serfdom vs bondage

serfdom and bondage both are nouns.

Word	Noun	Adjective	Verb	Adverb
serfdom	Yes	No	No	No
bondage	Yes	No	No	No

As nouns, bondage is a hypernym of serfdom; that is, bondage is a word with a broader meaning than serfdom:

Other hypernyms of serfdom include slavery, thraldom, thrall, thralldom.

serfdom (noun)	bondage (noun)
the state of a serf	sexual practice that involves physically restraining (by cords or handcuffs) one of the partners
	the state of being under the control of another person
	the state of being under the control of a force or influence or abstract power