Aboard ship, room for some biscuits in a tin (5)
I believe the answer is:
cabin
'aboard ship' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe there's a link between them I don't understand?
'room for some biscuits in a tin' is the wordplay.
'room' becomes 'i' (I can't explain this - if you can you should give a lot more credence to this answer).
'for' means one lot of letters go next to another (I've seen this in other clues).
'some' suggests taking the first letters.
'in' means one lot of letters goes inside another.
'a tin' becomes 'can' (synonyms).
The initial letter of 'biscuits' is 'b'.
'i' put after 'b' is 'bi'.
'bi' going into 'can' is 'CABIN'.
Can you help me to learn more?
(Other definitions for cabin that I've seen before include "Railway signal box" , "Hut or bothy" , "Hamper" , "Room on board ship" , "Compartment on a ship" .)