This is not a letter that is very commonly used in the English language, but it is considered as a symbol and when it appears in a dream, it means the desire of reaching the unknown.
Dream dictionary: mo k gh n bc do jh dream meanings
(arb. Unseen. See Five times prayers)
Remarking what was said with letter N, N letter in dream can be interpreted as the crowning of success, after many problems or many ups and downs that you had.
If this letter clearly appears in your dream it means that there will be success and failures that you will finally overcome if you keep up your courage and tenacity.