Language needing to be regularly repressed (4)
I believe the answer is:
erse
'language' is the definition.
(Erse is an example)
'to be regularly repressed' is the wordplay.
'to be regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
The alternate letters of 'repressed' are 'ERSE'.
'needing' acts as a link.
(Other definitions for erse that I've seen before include "Old Celtic language" , "Name sometimes given to languages of the Celts in Ireland and Scotland" , "Kind of Gaelic for seer" , "Possibly the language" , "Old language spoken by strange seer" .)