Fruit grew popular (7)
I believe the answer is:
rosehip
'fruit' is the definition.
(fruit of a rose plant)
'grew popular' is the wordplay.
'grew' becomes 'rose' (rise can mean to grow or increase).
'popular' becomes 'hip' (hip can mean trendy or popular).
'rose'+'hip'='ROSEHIP'
(Other definitions for rosehip that I've seen before include "Hedgerow or garden fruit" , "Fruit of the brier" , "Fruit of a popular flower" , "Fruit on wild plant" , "Fruit of the briar" .)