Girl tethers barking dog (5,6)
I believe the answer is:
irish setter
'dog' is the definition.
(Irish setter is an example)
'girl tethers barking' is the wordplay.
'girl' becomes 'iris' (**).
'barking' is an anagram indicator (UK slang for mad).
'tethers' anagrammed gives 'hsetter'.
'iris'+'hsetter'='IRISH SETTER'
(Other definitions for irish setter that I've seen before include "Dog from the Emerald Isle" , "Kind of dog" , "Breed of dog" , "Dog with dark red coat" , "best friend" .)