Perhaps he's right to gamble and drink (7)
I believe the answer is:
sherbet
'drink' is the definition.
(I've seen this before)
'perhaps he's right to gamble' is the wordplay.
'perhaps' indicates anagramming the letters.
'right' becomes 'r' (common abbreviation).
'to gamble' becomes 'bet' (betting is a kind of gambling).
'hes' is an anagram of 'she'.
'she'+'r'+'bet'='SHERBET'
'and' acts as a link.
(Other definitions for sherbet that I've seen before include "Fizzy stuff" , "Foreign beer" , "Powder for making fizzy drink" , "Sweet fizzy powder" , "Australian beer" .)