Catch nothing angling in lake, initially (4)
I believe the answer is:
nail
'catch' is the definition.
(nail can mean to catch or arrest)
'nothing angling in lake initially' is the wordplay.
'initially' suggests taking the first letters.
The initial letters of 'nothing angling in lake' is 'NAIL'.
(Other definitions for nail that I've seen before include "It needs a hammer (or a file?)" , "thing for keeping things together" , "Spike, tack" , "Fixing spike" , "Brad, say" .)