Ethnolinguistics is a field of linguistic anthropology which studies the language of a particular ethnic group.
Ethnolinguistics is frequently associated with minority linguistic groups within a larger population, such as the Native American languages or the languages of immigrants. In these cases, ethnolinguistics studies the use of a minority language within the context of the majority population, and it also studies the perception of the language by the majority population, for example whether the ethnic group receives state support to keep their language alive.
More generally, ethnolinguistics studies the relationship between language and culture, and the way different ethnic groups use their language to perceive the world. A well-known (but controversial) ethnolinguistic subject is the Sapir-Whorf Hypothesis, which states that perception is limited by what can be described in one's own language.
Ethnolinguists study the boundaries of perception created by language, and show how this is linked to different cultures and societies. An often stated example is the supposedly large number of words in Inuktitut for "snow," which may signify to an ethnolinguist that snow is an important part of Inuit culture.