Built European court with grass planted outside (7)
I believe the answer is:
erected
'built' is the definition.
(erecting is a kind of building)
'european court with grass planted outside' is the wordplay.
'european' becomes 'E' (abbreviation e.g. EU).
'court with' becomes 'ct' (abbreviation used in road names. I am not sure about the 'with' bit.).
'grass' becomes 'reed' (I've seen this before).
'planted outside' means one lot of letters goes inside another.
'ct' placed within 'reed' is 'rected'.
'e'+'rected'='ERECTED'
Can you help me to learn more?
(Other definitions for erected that I've seen before include "Put up (a building)" , "Set up" , "Fixed up" , "No Clue" , "Constructed, built" .)