Fruity type of Cava drunk entertaining Oscar at party (7)
I believe the answer is:
avocado
'fruity type' is the definition.
(I've seen this before)
'cava drunk entertaining oscar at party' is the wordplay.
'drunk' indicates anagramming the letters.
'entertaining' means one lot of letters goes inside another.
'oscar' becomes 'o' (phonetic alphabet: alpha, bravo, charlie etc.).
'at' is a charade indicator (letters next to each other).
'party' becomes 'do' (do is a kind of party).
'cava' with letters rearranged gives 'avca'.
'avca' enclosing 'o' is 'avoca'.
'avoca'+'do'='AVOCADO'
'of' is the link.
(Other definitions for avocado that I've seen before include "Pulpy fruit" , "A dark green pear with cramy flesh" , "Green-fleshed fruit" , "Shade of green" , "Fruity type" .)