Chandni
Chandni is not from the Qur'an or Hadith corpus; it is a Persian/Urdu poetic name meaning 'moonlight' used culturally by many Muslim families in South Asia and Iran.
The word is Persian/Urdu vocabulary (چاندنی) formed from 'chand' (moon) with a nisba-like adjectival form denoting 'of the moon' or 'moonlight.'
Yes — the term occurs widely in Persian and Urdu poetry as a descriptive term for moonlight and female beauty, and is attested in traditional songs and literary works of the Persianate milieu.
A close Arabic rendering of the meaning is نور القمر (nūr al-qamar) or ضوء القمر (ḍawʾ al-qamar), though the proper name Chandni remains Persian/Urdu in form.
In Urdu/Persian script it is written as چاندنی.