backseat vs inferiority

backseat and inferiority both are nouns.

Word	Noun	Adjective	Verb	Adverb
backseat	Yes	No	No	No
inferiority	Yes	No	No	No

As nouns, inferiority is a hypernym of backseat; that is, inferiority is a word with a broader meaning than backseat:

Other hypernyms of backseat include lower rank, lower status.

backseat (noun)	inferiority (noun)
a seat at the back of a vehicle (especially the seat at the back of an automobile)	an inferior quality
a secondary or inferior position or status	the quality of being a competitive disadvantage
	the state of being inferior