Where does “नीद” come from?

नीद (Old Marathi) comes from Sanskrit निद्रा, from Proto-Indo-Iranian *nidráH.

Ancestry of “नीद”, step by step

Step	Language	Word	Meaning
1	Sanskrit	निद्रा	sleep, slumber; to sleep
2	Proto-Indo-Iranian	*nidráH	—

नीद — Etymology, Origin & Word History | Etymology Explorer