In winter a suggestion brought up was worrying: remove one’s top? (10)
I believe the answer is:
decapitate
'top?' is the definition.
(I've seen this before)
'in winter a suggestion brought up was worrying' is the wordplay.
'in winter' becomes 'dec' (I am not sure about this - if you are sure you should believe this answer much more).
'suggestion' becomes 'tip' (tip is a kind of suggestion).
'brought up' says the letters should be written backwards (in a down clue, letters go up).
'was worrying' becomes 'ate' (eat can mean to worry or distress).
'tip' backwards is 'pit'.
'dec'+'a'+'pit'+'ate'='DECAPITATE'
'remove one's' is the link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for decapitate that I've seen before include "guillotine" , "To take top off" , "remove nut" , "Behead" .)