A place of growing importance (6)
I believe the answer is:
garden
'growing importance' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'a place' is the wordplay.
I cannot quite see how this works, but
'a' is found in the answer.
'place' could be 'den' (den is a kind of place) and 'den' is present in the answer.
This explanation may well be incorrect...
'of' acts as a link.
Can you help me to learn more?
(Other definitions for garden that I've seen before include "Area round house" , "Cultivate a plot" , "-- City; -- centre" , "Ranged (anag.)" , "nickname of US State" .)