### Clue: Object in 21 along with US lawyer holding capital (9)
### Answer: ANDROMEDA 
 ### Explanation: Definition: Object in 21
  [AND(along with) + DA(abbrev. for $$d$$istrict $$a$$ttorney, an American/US term for the prosecuting officer, who presumably is also a lawyer)] **containing**(holding) ROME(capital city). 
Answer: A constellation of stars in outer space(answer to 21across).