Is Elvis rocking? (5)
I believe the answer is:
lives
'is' is the definition.
('he is' means 'he lives')
'elvis rocking?' is the wordplay.
'rocking?' indicates an anagram (I've seen 'rocking' mean this).
'elvis' anagrammed gives 'LIVES'.
(Other definitions for lives that I've seen before include "Resides" , "Elvis (anag) - is not dead" , "See 5" , "Exists" , "Is animate" .)