Drink in vermouth sheepish male served up (7)
I believe the answer is:
martini
'drink' is the definition.
(martini is a kind of drink)
'in vermouth sheepish male served up' is the wordplay.
'vermouth' becomes 'it' (short for 'Italian vermouth' as in 'gin and it').
'sheepish male' becomes 'ram'.
'served up' is a reversal indicator.
'in'+'it'+'ram'='initram'
'initram' written backwards gives 'MARTINI'.
(Other definitions for martini that I've seen before include "Type of Italian vermouth" , "rifle" , "Cocktail of gin and dry vermouth" , "Cocktail made with gin or vodka and vermouth" , "Italian drink" .)