Burrow has royal starting to sool dogs (7)
I believe the answer is:
setters
'dogs' is the definition.
(setter is a kind of dog)
'burrow has royal starting to sool' is the wordplay.
'burrow' becomes 'sett' (I've seen this before).
'has' says to put letters next to each other.
'royal' becomes 'er' (abbreviation for Elizabeth Regina).
'starting to' indicates taking the first letters.
The initial letter of 'sool' is 's'.
'sett'+'er'+'s'='SETTERS'
(Other definitions for setters that I've seen before include "Crossword compilers" , "Canine" , "Long-haired gun dogs" , "eg Scottish, Gordon and 18" , "people like me" .)