Successfully deal with catch on end of line (4)
I believe the answer is:
cope
'successfully deal' is the definition.
(I've seen this before)
'catch on end of line' is the wordplay.
'catch' becomes 'cop' (cop can mean to arrest or apprehend).
'on' means one lot of letters go next to another.
'end of' suggests the final letters.
The final letter of 'line' is 'e'.
'cop'+'e'='COPE'
'with' is the link.
(Other definitions for cope that I've seen before include "Manage effectively" , "Deal well with difficulties" , "Deal effectively (with a difficulty)" , "investment" , "top on wall" .)