Heckle old-time entertainer heartlessly (4)

I believe the answer is:
jeer
'heckle' is the definition.
(I've seen this in another clue)
'entertainer heartlessly' is the wordplay.
'entertainer' becomes 'jester' (jester is a kind of entertainer).
'heartlessly' says to hollow out the word (remove centre letters).
'jester' with its centre taken out is 'JEER'.
'old-time' acts as a link.
I am not very happy about this link. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for jeer that I've seen before include "Taunt" , "Laugh at with derision" , "Rudely mocking remark" , "Call out derisively" , "Ridicule noisily" .)
