Is abound an adjective or a verb?

"Abound" is a verb. It means "to exist in large numbers or quantities".

Here's an example:

* "Fish abound in the lake." (meaning there are many fish in the lake)

While "abound" itself is not an adjective, there is a related adjective: abundant, meaning "existing in large quantities".

For example:

* "The garden was abundant with flowers." (meaning there were many flowers in the garden)