What is the difference between “uncertainty” and “uncertainly” [closed]

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.

Solution 1:

There is a big difference between them.

According to Cambridge Dictionary:

"uncertainly" is an ADVERB which means not confidently or surely.

"uncertainty" is a NOUN means a situation in which something is not known or certain.

She looked at John uncertainly. Life is full of uncertainties. I think that's a clear explanation.