noun, verbal noun, な adjective, の adjective
Remember how you learned that 凹凸 means "uneven?" Well spin something uneven around and it's still uneven! Just kinda backwards, just like this word!
However, just because the meaning stays the same when you flip it, doesn't mean the reading does. Doing that actually made the reading change from on'yomi to kun'yomi readings! You haven't learned either of these yet so here's a mnemonic to help you:
When you have the convex parts first and the concave parts second in something uneven it ends up looking like a deco box (でこぼこ). An art deco box that is. They have lots of stuff stick out of them on the outside, but you can open them up and put stuff on the inside.
I’m worried that the floor is a little uneven.