Context: I was reading a book and came across the word “uncertainty” as I never saw this word before it makes me confuse.
According to Dictionnary, the definition of uncertainty is:
The state of being uncertain.
But the definition of uncertainly is as follows:
With a lack of confidence or certainty.
So I really do not understand the difference between "Uncertainty" and "Uncertainly", both seem to express the fact of being not certain of something.