One who speaks or understands many languages

A. Scholar

B. Grammarian

C. Linguist

D. Polyglot

Answer: Option D

Solution(By Examveda Team)

One word substitute is Polyglot.

Scholar: a specialist in a particular branch of study, especially the humanities.
Grammarian: a person who studies and writes about grammar.
Linguist: a person skilled in foreign languages.
Polyglot: knowing or using several languages.