serfdom vs thrall

serfdom and thrall both are nouns.

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

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

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

serfdom (noun)	thrall (noun)
the state of a serf	someone held in bondage
	the state of being under the control of another person