oppression vs subjection

oppression and subjection both are nouns.

Word	Noun	Adjective	Verb	Adverb
oppression	Yes	No	No	No
subjection	Yes	No	No	No

As nouns, subjection is a hypernym of oppression; that is, subjection is a word with a broader meaning than oppression:

oppression: the state of being kept down by unjust use of force or authority:
subjection: forced submission to control by others

Other hypernyms of oppression include subjugation.

oppression (noun)	subjection (noun)
the act of subjugating by cruelty	the act of conquering
a feeling of being oppressed	forced submission to control by others
the state of being kept down by unjust use of force or authority: