Deer series being talked about (3)
I believe the answer is:
roe
'deer' is the definition.
(roe deer is a kind of deer)
'series being talked about' is the wordplay.
'series' becomes 'row' (I've seen this before).
'being talked about' shows a homophone (sound like).
'row' is a homophone of 'ROE'.
(Other definitions for roe that I've seen before include "Hoofed animal(s)" , "Part of fish, sounds like go through water" , "Mass of fish's eggs" , "shy animal" , "If hard, eggs" .)