Carp perhaps finding idealist sharing hacking tips (4)
I believe the answer is:
fish
'carp perhaps' is the definition.
(carp is a kind of fish)
'finding idealist sharing hacking tips' is the wordplay.
'tips' says to take the initial letters (tip can refer to the top end of something).
The initial letters of 'finding idealist sharing hacking' is 'FISH'.
(Other definitions for fish that I've seen before include "Angle, troll" , "Angle; trawl" , "Customer" , "Aquatic creature; rail-joining plate" , "Swimmer" .)