Language of nameless politician gets close to berserk (5)
I believe the answer is:
greek
'language' is the definition.
(Greek is an example)
'nameless politician gets close to berserk' is the wordplay.
'nameless politician' becomes 'gree' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'gets' is a charade indicator (letters next to each other).
'close to' indicates one should take the final letters (the close/ending of).
The final letter of 'berserk' is 'k'.
'gree'+'k'='GREEK'
'of' acts as a link.
Can you help me to learn more?
(Other definitions for greek that I've seen before include "Foreigner" , "Mediterranean native" , "One from Salonika" , "Hellenic" , "A native of Athens" .)