It's more appetising when in the hole (4)
I believe the answer is:
toad
'it's more appetising when' is the definition.
I can't tell whether this definition defines the answer.
'the hole' is the wordplay.
'the' becomes 't' (the is pronounced as a 't' sound in some dialects).
'hole' becomes 'oad' (I can't justify this - if you can you should give a lot more credence to this answer).
't'+'oad'='TOAD'
'in' is the link.
Can you help me to learn more?
(Other definitions for toad that I've seen before include "Warty amphibian" , "Loathsome creature" , "Warty creature" , "Wind in Willows hall-owner" , "A loathsome person" .)