No rest for singers (6)
I believe the answer is:
tenors
'for singers' is the definition.
(tenor is a singing voice)
'no rest' is the wordplay.
'no rest' anagrams to 'TENORS'.
However, I'm unsure how the anagram is indicated.
Can you help me to learn more?
(Other definitions for tenors that I've seen before include "Male singing voices" , "Opera singers" , "Male singers with high register" , "Male singers from Reston" .)