Nirvana is a neutral word, so it will be nirvaaNam in Sanskrit.

Vidya (Vidyaa, long a , a feminine word) means knowledge. Veda is the name of the old scriptures. Also Veda has the verbal root "vid" which means to know.
That is vid in the second conjugation. "He knows" is in Sanskrit "vetti". But there is also a vid in the fourth conjugation. In this conjugation vid means "to be, to be present, to exist" He is = vidyate. There is also vid in the sixth conjugation. In this conjugation vid means "to find", he finds = vindati.
So the vedas are "sacchidaananda" (sat-chit-aananda)
All the three words has a corresponding verbal root of vid.
sat = vid 6th conjugation, vidyate. Sat is to be. The supreme thruth, which always existed and will be existing in the future.
chid = consciousness, vid 2nd conjugation, vetti. Consciousness is knowing.
Ananda = happiness, bliss. vid 4th conjugation, vindati. searching and finding happiness.

I will give Nirvana, vidya, veda (singular and plural) in Devanagari scripts along with Roman Transcription.