Finally get hold of dog with fluffy hair (5,4)
I believe the answer is:
track down
'finally get hold' is the definition.
I can't judge whether this defines the answer.
'dog with fluffy hair' is the wordplay.
'dog' becomes 'track' (synonyms).
'with' means one lot of letters go next to another.
'fluffy hair' becomes 'down' (I've seen this before. I am not sure about the 'fluffy' bit.).
'track'+'down'='TRACK DOWN'
'of' acts as a link.
Can you help me to learn more?
(Other definitions for track down that I've seen before include "Find (something) after long search" , "path from the summit" , "what railway constructor needs to get" , "Finally discover" , "railway's state after landslide?" .)