thrall vs serf

thrall and serf both are nouns.

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

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

thrall: someone held in bondage
serf: (Middle Ages) a person who is bound to the land and owned by the feudal lord

Other hyponyms of thrall include helot, villein.

thrall (noun)	serf (noun)
someone held in bondage	(Middle Ages) a person who is bound to the land and owned by the feudal lord
the state of being under the control of another person