If you are asking whether it’s ok to quote the dictionary in a (any) paper, the answer is yes, of course. You can quote anything (with proper citation) provided that the quotation isn’t so long as to decrease the value of the original work.
There are only so many ways to define a word. Dictionary writers try to avoid knowingly using each other’s language, but even they acknowledge that there’s going to be a lot of similarity if you are getting at the essence of a word.
If the point of your paper is to write an extended definition (a type of essay), you can still start with a dictionary. What follows must be your own, and any quotation must be credited.
BUT it may not be okay to quote the dictionary in this paper. It sounds like that restriction may have something to do with the assignment. Whatever the reason, your first job is to fulfill the requirements of the assignment.
@alive, anything can be dry if you don’t love it. I love dictionaries and greatly admire the lexicographer’s art. So they are not dry to me. Still, I wouldn’t generally recommend them for leisure reading.