Is poverty an adjective

No, it's a noun. It's technically a state of being, or idea noun. Nouns are people, places, things, or ideas, which most people forget. An idea is something that's not tangible and can't be shown as an image (but can be conveyed through images). Love is an idea noun, as is poverty, hate, intelligence, etc.

An adjective derived from poverty would be poverty-stricken.