posterior vs torso

posterior and torso both are nouns.

Word	Noun	Adjective	Verb	Adverb
posterior	Yes	Yes	No	No
torso	Yes	No	No	No

posterior (noun)	torso (noun)
the fleshy part of the human body that you sit on	the body excluding the head and neck and limbs
a tooth situated at the back of the mouth

posterior (adjective)	torso (adjective)
located at or near or behind a part or near the end of a structure
coming at a subsequent time or stage