The meaning of the word 'nocturnal' is-

The meaning of the word 'nocturnal' is- Occurring or active at night.

Nocturnal (Adj)
Bangla Meaning: নৈশ; নিশাচর: nocturnal birds; a man of nocturnal habits.
English Meaning: of, relating to, or occurring in the night.

Example Sentence:
- "Most owls are nocturnal."
- "Max has the night beat, circling a nocturnal but always active Los Angeles."

Source: Merriam-Webster Dictionary, Accessible Dictionary.