Cross-bred dog (7)
I believe the answer is:
lurcher
'cross-bred dog' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for lurcher that I've seen before include "Dog related to greyhound" , "The dog to stagger" , "one unsteady on his feet" , "canine cross?" , "incapable of steady gait?" .)