posterior vs spatial relation

posterior and spatial relation both are nouns.

Word	Noun	Adjective	Verb	Adverb
posterior	Yes	Yes	No	No
spatial relation	Yes	No	No	No

posterior (noun)	spatial relation (noun)
the fleshy part of the human body that you sit on	the spatial property of a place where or way in which something is situated
a tooth situated at the back of the mouth

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