Nehan (which can also be said as Nahan) is a Farsi word that means hidden, secret, in secret. covered. It is used for both boys and girls. It is not an Arabic or Quranic word, but since the meaning is not bad, Muslims can use it.
سخنی در نهان نباید گفت
که به هر انجمن نشاید گفت .
A speech mustn't be said in secret
That one wouldn't say in every gathering
-Saadi Shirazi (Persian poet)
Nehan is pronounced as (N)ame + p(E)n + (HA)rd + (N)ame and also (N)ame + p(I)n + (HA)rd + (N)ame
Nahan is pronounced as (NU)mber + (HA)rd + (N)ame