tub vs vessel

tub and vessel both are nouns.

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

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

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

tub: a relatively large open container that you fill with water and use to wash the body
vessel: an object used as a container (especially for liquids)

tub (noun)	vessel (noun)
a large open vessel for holding or storing liquids	a craft designed for water transportation
a relatively large open container that you fill with water and use to wash the body	an object used as a container (especially for liquids)
the amount that a tub will hold	a tube in which a body fluid circulates