### Clue: Unsettled round greenery, last rook departs (7)
### Answer: OVERDUE 
 ### Explanation: Definition: Unsettled
 O(letter representing a circular shape/round) + "verdure"(greenery/lush green vegetation) **minus its second/last of 2**(last … departs) "r"(abbrev. for "rook", in chess notation).
Defn: …, describing a debt not paid when due.