what is 'a small congenital spot on the human skin, usually dark-coloured' I need a synonym of the description

Question

it's part of a crossword-puzzle at school I can't find the answer. I still need two other words.
This word has 6 letters, the 3rd is an N and it ends with a D

Answer 1

I tried looking it up. The definition brought up mole, so I looked it up in the thesaurus. None of the synonyms match so maybe the letters are incorrect. Here is the link in case you discover that you made an error.

Answer 2

Are you sure on the letters?

possibly CANCER if the D is questionable