Followed a sort of red-tail (7)
I believe the answer is:
trailed
'followed' is the definition.
(I've seen this in another clue)
'a sort of red-tail' is the wordplay.
'a sort of' is an anagram indicator.
'red'+'tail'='redtail'
'redtail' is an anagram of 'TRAILED'.
(Other definitions for trailed that I've seen before include "Followed or tracked after" , "Dragged" , "Lagged behind" .)