thrall vs serfdom

thrall and serfdom both are nouns.

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

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

Other hyponyms of thrall include bonded labor, servitude, serfhood, vassalage.

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