Traditional conservative girl I ring endlessly (9)
I believe the answer is:
classical
'traditional' is the definition.
(I've seen this before)
'conservative girl i ring endlessly' is the wordplay.
'conservative girl' becomes 'class' (I've seen this in other clues. I am not sure about the 'conservative' bit.).
'ring' becomes 'call' (synonyms).
'endlessly' means to remove the last letter.
'call' with its final letter taken off is 'cal'.
'class'+'i'+'cal'='CLASSICAL'
(Other definitions for classical that I've seen before include "Like some music" , "Traditionally accepted" , "'highbrow'?" , "Relating to ancient Greek and Latin cultures" , "Of recognized excellence, music perhaps" .)