What term describes differing varieties of a language that may be considered less socially acceptable?

The term that best describes differing varieties of a language that may be considered less socially acceptable is "dialects of a language." Dialects encompass variations in pronunciation, grammar, vocabulary, and usage that can arise from geographical, social, or cultural differences. While all dialects are legitimate forms of communication, some may carry stigmas or be viewed as less prestigious compared to the standardized forms of that language.

Diverse accents, while they do represent variations of pronunciation, do not encompass the broader grammatical and lexical differences that define dialects. Standardized forms of language are typically those that are taught and accepted in formal contexts, often seen as authoritative. Slang variations refer to informal language that can fluctuate rapidly and is used within specific social groups, but does not capture the full spectrum of regional and social dialects that may be viewed as less socially acceptable. Thus, the notion of dialects specifically addresses both the variety within a language and the social perceptions associated with those different forms.