Terrible lies about very old pop star (5)
I believe the answer is:
elvis
'old pop star' is the definition.
The definition suggests a singular noun which matches the answer.
'terrible lies about very' is the wordplay.
'terrible' is an anagram indicator.
'about' indicates putting letters inside.
'very' becomes 'v' (abbreviation).
'lies' anagrammed gives 'elis'.
'elis' placed around 'v' is 'ELVIS'.
Can you help me to learn more?
(Other definitions for elvis that I've seen before include "The familiar R 'n'Roll king" , "Singer Presley" , "The King, d. 1977" , "Deceased king of rock 'n' roll" , "Musically, The King" .)