Youth, including one assigned position on ground (4)
I believe the answer is:
laid
'assigned position on ground' is the definition.
The definition and answer can be both to do with ownership as well as being past participle verbs.
Maybe you can see a link between them that I don't see?
'youth including one' is the wordplay.
'youth' becomes 'lad' (lad means a young man).
'including' indicates putting letters inside.
'one' becomes 'i' (Roman numeral).
'lad' going around 'i' is 'LAID'.
Can you help me to learn more?
(Other definitions for laid that I've seen before include "(Of dining table) set" , "Put down like dial" , "Wagered" , "tables may be?" , "settled" .)