The French -- after unusually quiet drink (7)
I believe the answer is:
tequila
'drink' is the definition.
(tequila is a kind of drink)
'the french after unusually quiet' is the wordplay.
'the french' becomes 'la'.
'after' means one lot of letters go next to another.
'unusually' indicates anagramming the letters.
'quiet' with letters rearranged gives 'tequi'.
'la' put after 'tequi' is 'TEQUILA'.
(Other definitions for tequila that I've seen before include "Mexican alcoholic drink" , "Distilled agave drink" , "Cocktail -- 1988 American crime film -- equaliser units (anag)" , "Is there another drink to equal it?" , "Mexican liquor made from agave" .)