Row about two appearances of good friend to Pooh (6)
I believe the answer is:
tigger
'friend to pooh' is the definition.
(Winnie the Pooh character)
'row about two appearances of good' is the wordplay.
'row' becomes 'tier' (tier is a kind of row).
'about' is an insertion indicator.
'two appearances of' shows that letters should be duplicated.
'good' becomes 'g' (abbreviation).
'g' duplicated is 'gg'.
'tier' going around 'gg' is 'TIGGER'.
(Other definitions for tigger that I've seen before include "Bouncy friend of 19" , "8's friend (the bouncy one)" , "friend of Pooh" , "Bouncy beast (Pooh)" , "Pooh's bouncy friend" .)