steeper vs vessel

steeper and vessel both are nouns.

Word	Noun	Adjective	Verb	Adverb
steeper	Yes	No	No	No
vessel	Yes	No	No	No

As nouns, vessel is a hypernym of steeper; that is, vessel is a word with a broader meaning than steeper:

steeper (noun)	vessel (noun)
a vessel (usually a pot or vat) used for steeping	a craft designed for water transportation
	an object used as a container (especially for liquids)
	a tube in which a body fluid circulates