Store roofless Jeep beneath lower deck (4)
I believe the answer is:
keep
'store' is the definition.
(I know that keep is a kind of store)
'roofless jeep beneath lower deck' is the wordplay.
'roofless' means to remove the first letter.
'beneath' means one lot of letters go next to another (in a down clue, some letters go below others).
'lower deck' becomes 'k' (I can't justify this - if you can you should give a lot more credence to this answer).
'jeep' with its initial letter removed is 'eep'.
'eep' after 'k' is 'KEEP'.
Can you help me to learn more?
(Other definitions for keep that I've seen before include "Hold - fortress" , "Remain" , "Hold - part of castle" , "Fort" , "Board and lodging" .)