Interest at regular camp for ring (6)
I believe the answer is:
appeal
'interest' is the definition.
(I've seen this before)
'regular camp for ring' is the wordplay.
'regular' indicates alternate letters.
'for' is a charade indicator (letters next to each other).
'ring' becomes 'peal' (synonyms).
The alternate letters of 'camp' are 'ap'.
'ap'+'peal'='APPEAL'
'at' acts as a link.
(Other definitions for appeal that I've seen before include "A crustacean" , "Request hearing of higher court" , "Legal procedure" , "Power to interest" , "Pray, invoke" .)