Persuade merry old king to receive heads of Al Jazeera (6)
I believe the answer is:
cajole
'persuade' is the definition.
(I know this)
'merry old king to receive heads of al jazeera' is the wordplay.
'merry old king' becomes 'cole' (I've seen this in another clue).
'to receive' is an insertion indicator.
'heads of' says to take the initial letters.
The first letters of 'al jazeera' is 'aj'.
'cole' going around 'aj' is 'CAJOLE'.
(Other definitions for cajole that I've seen before include "Urge by gentle flattery" , "Inveigle by gentle urging" , "'Coax, sweet-talk (6)'" , "Coax through flattery" , "Persuade by coaxing" .)