n.
A set of similar dialects constituting any of the larger distinct regional varieties of a language. For example, Mandarin Chinese is a topolect that includes the dialects of Beijing and Nanjing, and is distinct from Hakka, another topolect of Chinese.
[TOPO- + (DIA)LECT (translation of Chinese (Mandarin) fāngyán, regional speech : fāng, place + yán, language).]
