Anglers regularly cast out for a long time (4)
I believe the answer is:
ages
'long time' is the definition.
(I've seen this in another clue)
'anglers regularly' is the wordplay.
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
The alternating letters of 'anglers' are 'AGES'.
'cast out for a' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for ages that I've seen before include "Matures" , "Awfully long time" , "Grows old like sage" , "Gets older" , "... of Man, according to WB Yeats" .)