The rumor was completely without foundation.
One of the suitcases is completely empty.
The data was completely useless.
The building was completely destroyed.
The boxing match was completely one-sided, one pug was so badly mauled that his manager had to throw in the sponge.
The child was completely lacking in discipline.
The question foxed me completely.
In that respect, I agree with you completely.
The answer is completely wrong.
So far as this matter is concerned, I am completely satisfied.