Say they're in bunk having this kind of toast? (8)
I believe the answer is:
buttered
'bunk having this kind of toast?' is the definition.
The answer and definition are different parts of speech. However, adjectives and past participle verbs can occasionally mean the same thing.
'say they're in' is the wordplay.
'say' becomes 'utter' (to utter something is to speak or say it).
'they're' becomes 'bed' (I can't explain this - if you can you should give a lot more credence to this answer).
'in' is an insertion indicator.
'utter' inserted into 'bed' is 'BUTTERED'.
Can you help me to learn more?
(Another definition for buttered that I've seen is " Covered with dairy spread".)