What is a suffix to competeally?

There is no suffix that can be added to "completely" to create a new word.

"Completely" is already a complete word and doesn't need any further additions.

If you're looking for ways to express a similar idea, you could consider using:

* Adverbs like "totally", "utterly", "entirely"

* Phrases like "to the fullest extent", "without exception", "in every way"

For example, instead of "completely finished", you could say:

* "totally finished"

* "utterly finished"

* "finished to the fullest extent"

Remember, the best choice will depend on the specific context and desired tone.