slavery vs subjugation

slavery and subjugation both are nouns.

Word	Noun	Adjective	Verb	Adverb
slavery	Yes	No	No	No
subjugation	Yes	No	No	No

As nouns, subjugation is a hypernym of slavery; that is, subjugation is a word with a broader meaning than slavery:

Other hypernyms of slavery include subjection.

slavery (noun)	subjugation (noun)
work done under harsh conditions for little or no pay	the act of conquering
the practice of owning slaves	the act of subjugating by cruelty
the state of being under the control of another person	forced submission to control by others