joint vs united

joint is a noun but united is not a noun.

Word	Noun	Adjective	Verb	Adverb
joint	Yes	Yes	Yes	No
united	No	Yes	No	No

joint (noun)	united (noun)
marijuana leaves rolled into a cigarette for smoking
junction by which parts or objects are joined together
a disreputable place of entertainment
(anatomy) the point of connection between two bones or elements of a skeleton (especially if it allows motion)
a piece of meat roasted or for roasting and of a size for slicing into more than one portion
the shape or manner in which things come together and a connection is made

joint (adjective)	united (adjective)
united or combined	characterized by unity; being or joined into a single entity
involving both houses of a legislature	of or relating to two people who are married to each other
affecting or involving two or more	involving the joint activity of two or more