Enlargement, growth (9)
I believe the answer is:
expansion
I believe this is a double definition.
'enlargement' is the first definition.
(I know that enlargement can be written as expansion)
'growth' is the second definition.
(thesaurus)
(Other definitions for expansion that I've seen before include "Enlargement" , "Increase in volume" , "increase in capacity" , "Process of increasing in size, volume etc" , "fatter" .)