Important German city Italy almost rebuilt (9)
I believe the answer is:
essential
'important' is the definition.
(associated in meaning)
'german city italy almost rebuilt' is the wordplay.
'german city' becomes 'essen' (city in Germany).
'almost' means to remove the last letter (most of the word but not all of it).
'rebuilt' is an anagram indicator.
'italy' with its final letter taken off is 'ital'.
'ital' is an anagram of 'tial'.
'essen'+'tial'='ESSENTIAL'
(Other definitions for essential that I've seen before include "organic" , "Indispensable, necessary" , "So is certain oil-production" , "absolutely neccessary?" , "as oil might be" .)