Cask from King's Head, for example (3)
I believe the answer is:
keg
'cask' is the definition.
(I know that keg is a type of cask)
'king's head for example' is the wordplay.
'head' suggests taking the first letters.
'for example' becomes 'eg' (short for 'exempli gratia', 'for example' in Latin).
The initial letter of 'kings' is 'k'.
'k'+'eg'='KEG'
'from' is the link.
(Other definitions for keg that I've seen before include "What's found at King's Head" , "Barrel as for beer" , "Small cask or barrel" , "Small beer cask" , "Sort of beer" .)