Not settled round greenery, second rook departs (7)
I believe the answer is:
overdue
'not settled round greenery second' is the definition.
Both the answer and definition are adjectives. Perhaps there's an association between them I don't understand?
'rook departs' is the wordplay.
I cannot quite understand how this works, but
'rook' could be 'r' (abbreviation in chess) and 'r' is found in the answer.
'departs' could be 'd' (common abbreviation e.g. train timetables) and 'd' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for overdue that I've seen before include "Past the expected time of arrival" , "Late arriving" , "Later than the appointed time, as for bill payment" , "Still unpaid" , "Remaining unpaid after the scheduled time" .)