A person who knows many languages is known as:

A person who knows many languages is known as: polyglot.

Polyglot (Noun)
Bangla Meaning: বহুভাষিক; বহুভাষী; বহুভাষিক পুস্তক।
English Meaning: one who is polyglot.

Teetotaler (Noun)
Bangla Meaning: যিনি মদ্যপান থেকে বিরত থাকেন।
English Meaning: one who practices or advocates teetotalism.

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

Source: Merriam-Webster Dictionary, Accessible Dictionary.