dialect · noun C or U /ˈdɑɪ.ə.lekt/
dialect
C2 a form of a language that people speak in a particular part of a country
Dictionary example:
They're speaking a local dialect.
Learner example:
Mrs Haefele, the owner and cook of this inn, serves the meals personally and if you are lucky, you [may] understand a bit of her Swabian dialect. (Certificate of Proficiency in English; C2; German)