… sheep circling about in pursuit of a drink (9)
I believe the answer is:
americano
'drink' is the definition.
(type of coffee drink)
'sheep circling about in pursuit of a' is the wordplay.
I cannot quite understand how this works, but
'about' could be 'ca' (abbreviation for 'circa') and 'ca' is present in the answer.
'sheep' could be 'merino' (breed of sheep) and 'merino' is found within the remaining letters.
'a' is within the answer.
This accounts for all the letters.
This explanation may well be incorrect...
(Other definitions for americano that I've seen before include "drink" , "Style of coffee" , "Espresso diluted with hot water" .)