Can the word deplore be used as a noun?

No, the word "deplore" is not a noun. It is a verb, meaning to express strong disapproval of something.

While it might sound like a noun because it ends in "-ore," there is no noun form of "deplore".

If you want to use the concept of strong disapproval as a noun, you could use words like:

* Deploration

* Condemnation

* Reprobation

* Censure

* Disapproval