existent vs concrete

existent is not a noun while concrete is a noun.

Word	Noun	Adjective	Verb	Adverb
existent	No	Yes	No	No
concrete	Yes	Yes	Yes	No

existent (noun)	concrete (noun)
	a strong hard building material composed of sand and gravel and cement and water

existent (adjective)	concrete (adjective)
having existence or being or actuality	capable of being perceived by the senses; not abstract or imaginary
being or occurring in fact or actuality; having verified existence; not illusory	formed by the coalescence of particles
presently existing in fact and not merely potential or possible

existent (verb)	concrete (verb)
	form into a solid mass; coalesce
	cover with cement