Pessimistic, vintage being ruined by tail of hurricane (8)
I believe the answer is:
negative
'pessimistic' is the definition.
('negative' is associated in meaning with 'pessimistic')
'vintage being ruined by tail of hurricane' is the wordplay.
'being ruined' indicates anagramming the letters.
'by' says to put letters next to each other.
'tail of' says to take the final letters.
The last letter of 'hurricane' is 'e'.
'vintage' is an anagram of 'negativ'.
'negativ'+'e'='NEGATIVE'
(Other definitions for negative that I've seen before include "Get a vine (anag.)" , "Less than zero quantity" , "'Pessimistic, gloomy (8)'" , "Defeatist" , "Not positive - denial" .)