noun
sociolinguistics
Academic field studying the relationship between language and society.
彼女は大学で社会言語学を専攻している。
She is majoring in sociolinguistics at university.
言語学 is general linguistics, while 社会言語学 specifically focuses on the social aspects of language.
Compound of 社会 (society) and 言語学 (linguistics), a calque from English 'sociolinguistics'.