Does the word existingly exist as an adverb?

No, the word "existingly" does not exist as an adverb in standard English.

While it might seem like a logical formation from the adjective "existing," it's not a word that's commonly used or recognized.

If you want to express the idea of "in an existing way," you can use other adverbs like:

* Currently

* Presently

* Already

* Previously

* Actually

For example:

* "The building is currently occupied."

* "The rules are already in place."

* "The project was previously completed."