Which word means a regional variation of a language?

A. Dialect

B. Slang

C. Culture

D. Ethnicity

The answer is A, Dialect.

Explanation:

The term dialect is used in two distinct ways to refer to two different types of linguistic phenomena: One usage refers to a variety of a language that is a characteristic of a particular group of the language's speakers.

A. Dialect

The word dialect means a language spoken differently within a region or social group.