Horticulture is on the increase (7)
I believe the answer is:
growing
This clue could be a double definition.
'horticulture' is the first definition.
Although both the answer and definition are singular nouns, I cannot understand how one could define the other.
'on the increase' is the second definition.
(I've seen this before)
'is' is the link.
Can you help me to learn more?
(Other definitions for growing that I've seen before include "crescent" , "On the increase" , "Increasing in size and changing" , "Developing, maturing" , "Increasing in magnitude" .)