Cut odd bits in cargo up (4)
I believe the answer is:
crop
'cut' is the definition.
(cropping is a kind of cutting)
'odd bits in cargo up' is the wordplay.
'bits' says to take the initial letters (I've seen 'bit of' mean this).
'in' indicates putting letters inside.
'cargo' becomes 'prc' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'up' says the letters should be written backwards (in down clue: letters go upwards).
The initial letter of 'odd' is 'o'.
'o' put inside 'prc' is 'porc'.
'porc' reversed gives 'CROP'.
Can you help me to learn more?
(Other definitions for crop that I've seen before include "supply" , "distress, as it were" , "Short cut - taken when hunting?" , "Set" , "(Yield from) cultivated plant" .)