### Clue: Keep mum working at a foreign language (5)
### Answer: SHONA 
 ### Explanation: Definition: foreign language
 SH!(an interjection to keep mum;be silent) + ON(working, as, say, with an electrical appliance) **plus**(at) A.
Defn: … of the African people of the same name, belonging to the Bantu group of languages.