Poem sung about Zulu being idle (4)
I believe the answer is:
lazy
'idle' is the definition.
(similar in meaning)
'poem sung about zulu' is the wordplay.
'poem sung' becomes 'lay'.
'about' indicates putting letters inside.
'zulu' becomes 'Z' (phonetic alphabet: alpha, bravo, charlie etc.).
'lay' going around 'z' is 'LAZY'.
'being' is the link.
(Other definitions for lazy that I've seen before include "Averse to labour" , "Averse to exertion" , "Unwilling to work" , "Slothful" , "Disinclined to work" .)