The word joint is a noun. The plural form is joints.
It is either an adjective or a noun depending on its usage in a sentence. For the most part, however, it is a noun.
Arthr(o) is the root word that closely means "joint."
The part of speech for this particular word is a noun.
part of speech
The part of speech for "answer" is a noun.
what part of speech is beneath
adverb
Ball and Socket joint
The part of speech for "explicit" is an adjective.
The part of speech for "lecturer" is a noun.
The part of speech for "rapid" is an adjective.
The part of speech of "came" is a verb.