母語

Etymology
.

Noun

 * 1) mother tongue; native language; first language
 * 2) ancestral language
 * 3) official mandated language of one's ethnic group
 * 1) ancestral language
 * 2) official mandated language of one's ethnic group
 * 1) ancestral language
 * 2) official mandated language of one's ethnic group
 * 1) official mandated language of one's ethnic group
 * 1) official mandated language of one's ethnic group

Etymology 1
.

Noun

 * 1) a first language, a mother tongue, a native tongue, a native language

Etymology 2
, or of.

Noun

 * 1)  a proto-language, a mother language

Usage notes
In this sense, has been largely superseded by the term.