Language used by coarser servants (4)
I believe the answer is:
erse
'language' is the definition.
(Erse is an example)
'used by coarser servants' is the wordplay.
'used by' says the answer is hidden in the clue.
'ERSE' is hidden within 'coarser servants'.
(Other definitions for erse that I've seen before include "Old name for Celtic languages" , "Old Celtic language" , "Name sometimes given to languages of the Celts in Ireland and Scotland" , "Kind of Gaelic for seer" , "Old Scots or Irish Gaelic" .)