Two pawns swallowed by sort of white dog (7)
I believe the answer is:
whippet
'dog' is the definition.
(whippet is a kind of dog)
'two pawns swallowed by sort of white' is the wordplay.
'two pawns' can mean two substitutions for 'pawn'.
'pawn' becomes 'p'.
'pawn' becomes 'p'.
'swallowed by' means one lot of letters goes inside another.
'sort of' is an anagram indicator.
'p'+'p'='pp'
'white' is an anagram of 'whiet'.
'pp' going into 'whiet' is 'WHIPPET'.
(Other definitions for whippet that I've seen before include "racing animal" , "Racing-dog" , "Small slender breed of dog like a greyhound" , "Dog similar to a greyhound" , "dog class?" .)