Some submarine trap? (3)
I believe the answer is:
net
'some submarine trap?' is the definition.
'net' can be an answer for 'trap?' (net is a kind of trap). I'm not sure about the 'some submarine' bit.
'some submarine trap?' is the wordplay.
'some' indicates a hidden word (some of the parts of the word are used).
'NET' is hidden in the letters of 'submarine trap'.
Can you help me to learn more?
(Other definitions for net that I've seen before include "Fish-catching mesh" , "Final profit when all overheads have been deducted" , "Score a goal" , "Open-meshed material (used for catching things?)" , "Open-mesh fabric" .)