oppression vs oppressiveness

oppression and oppressiveness both are nouns.

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

As nouns, oppression and oppressiveness are synonyms defined as:

oppression (noun)	oppressiveness (noun)
the act of subjugating by cruelty	unwelcome burdensome difficulty
a feeling of being oppressed	a feeling of being oppressed
the state of being kept down by unjust use of force or authority: