Bizarrely, "our big hen" is how Sunak might describe Johnson (9)
I believe the answer is:
neighbour
'how sunak might describe johnson' is the definition.
I can't tell whether this defines the answer.
'bizarrely our big hen' is the wordplay.
'bizarrely' indicates anagramming the letters.
'our'+'big'+'hen'='ourbighen'
'ourbighen' with letters rearranged gives 'NEIGHBOUR'.
'is' acts as a link.
Can you help me to learn more?
(Other definitions for neighbour that I've seen before include "Chap next door" , "One who must live alongside" , "One living close by" , "sit next to" , "lovable person?" .)