Its end can be hurtful! (4)
I believe the answer is:
rope
'be hurtful' is the definition.
I can't tell whether this defines the answer.
'its end can' is the wordplay.
'its' becomes 'ro' (I am not sure about this - if you are sure you should believe this answer much more).
'end' means to remove the middle letters (I've seen 'ends' mean this).
'can' becomes 'preserve' (preserve in a can).
'preserve' with its middle taken out is 'pe'.
'ro'+'pe'='ROPE'
Can you help me to learn more?
(Other definitions for rope that I've seen before include "Stranded fastener" , "String of pearls, say" , "murder weapon" , "Enough to hang one?" , "Pore (anag.)" .)