Tall tales of fish rising on poles (5)
I believe the answer is:
yarns
'tall tales' is the definition.
(I've seen this in another clue)
'fish rising on poles' is the wordplay.
'fish' becomes 'ray' (ray is a kind of fish).
'rising' says the letters should be written backwards (going up in a down clue).
'on' says to put letters next to each other.
'poles' becomes 'ns' (North and South poles).
'ray' back-to-front is 'yar'.
'yar'+'ns'='YARNS'
'of' is the link.
(Other definitions for yarns that I've seen before include "Anecdotes" , "Wools or stories" , "Stories, threads" , "Tales; threads" , "Threads spun from wool, cotton, etc." .)