Drink mint tea, we hear -- right with vichy water (9)
I believe the answer is:
cointreau
'drink' is the definition.
(type of liqueur)
'mint tea we hear right with vichy water' is the wordplay.
'mint' becomes 'coin' (synonyms).
'we hear' indicates a 'sounds like' (homophone) clue.
'right' becomes 'r' (common abbreviation).
'with' means one lot of letters go next to another.
'vichy water' becomes 'eau' ('water' in French - eg in the French town Vichy).
'tea' sounds like 't'.
'coin'+'t'+'r'+'eau'='COINTREAU'
(Other definitions for cointreau that I've seen before include "Alcoholic drink" , "Orange liqueur" , "A sweet orange-flavoured liqueur for cautioner" , "Sweet orange-flavoured colourless liqueur" .)