Across

1. Living in the absence of free air or oxygen

6. Round, flat West Asian bread

8. Large cat native to Africa and Southern Asia

11. Edible, succulent, pungent bulb

12. A portable firearm

13. A system or collection of rules

14. Republic in West Africa

17. American Federal agency for aeronautical research (abbv.)

19. ___ Khan, Pakistani President from 1958-1969

21. One of the three Magi or wise men in the Bible.

Down

2. An Indian residing abroad (abbv.)

3. Impetuous ardour, dash

4. Capital of Norway

5. International Standardisation Organisation (abbv.)

6. Irreligious or hedonistic

7. Pair of ___, two armed hinged instrument used for holding or lifting something

9. The Taj Mahal is decorated with this type of work

10. An honorary title conferred upon Muslims of distinction in India and Pakistan

15. A male deer, commonly the red deer

16. A member of the Nagaland tribes

18. Exposure index of a photographic film is measured in this (abbv.) 

20. A western super power (abbv.)