Varied riots occupying left-wingers in Havana in case of importance (8)
I believe the answer is:
historic
'in havana in case of importance' is the definition.
I can't tell whether this definition defines the answer.
'varied riots occupying left-wingers' is the wordplay.
'varied' indicates an anagram.
'occupying' means one lot of letters goes inside another.
'left wingers' becomes 'hic' (I can't justify this - if you can you should believe this answer much more).
'riots' is an anagram of 'stori'.
'stori' placed inside 'hic' is 'HISTORIC'.
Can you help me to learn more?
(Other definitions for historic that I've seen before include "Memorable" , "Pertaining to what is important in the past" , "Significant" , "Redolent of past glories" , "sort of present" .)