She may drunkenly set about a large dog (8)
I believe the answer is:
sealyham
'dog' is the definition.
(Sealyham is an example)
'she may drunkenly set about a large' is the wordplay.
'drunkenly' indicates an anagram.
'set about' indicates putting letters inside.
'large' becomes 'l'.
'she'+'may'='shemay'
'shemay' with letters rearranged gives 'seyham'.
'a'+'l'='al'
'seyham' enclosing 'al' is 'SEALYHAM'.
(Other definitions for sealyham that I've seen before include "A shy male (anag) - dog" , "Breed of terrier" , "5 [MANS BEST FRIEND]" , "Dog that rhymes with ..." , "Hay meals (anag) - kind of terrier" .)