1. London radio station
4. Relative biological effectiveness, abbr.
7. Country
12. Also
13. Own (Scottish)
14. Rhizopod
15. A former Soviet republic
17. A wealthy man (who made his fortune in the Orient)
18. Curious
19. Actress ___ Ryan
21. Pericarp
22. An unofficial association of people
24. Small amount
25. Any of numerous rigid or bristly and springy organs or parts of animals or plants
26. Chordophone
27. Gambling hall
29. Ancient Persia ruler
31. State capital
35. In a way, integrated
37. Annoy constantly
38. Air pollution
41. Radioactivity unit
42. Mexican Indian
43. Records electric currents generated by the brain
44. The residue that remains when something is burned
45. Brother or sister
46. More scarce
48. Produces a chemical vapor to be inhaled in order to relieve nasal congestion
52. Oil
53. Drive
54. Ethiopia (Abbrev)
55. Chemical decomposition or splitting of molecules or cells
56. Big Blue
57. Portuguese for "Saint"
2. Derek __, Harvard
3. Margin between the skin of the pastern and the horn of the hoof
4. Military surprise attack
5. Container
6. Curatives
7. Sounded a bell
8. Fringe-toed lizard
9. Jewish spiritual leader
10. Concerning
11. __dor, part of Newfoundland
16. Sum up
22. Mass transit vehicle
23. Alias
24. Odd-toed ungulates
25. Standing operating procedure
27. A sealed tin container
28. A silent affirmative
30. Floor covering
32. Empowers
33. Mary __, cosmetics
34. Honorable title (Turkish)
38. Coal formation
39. Slang for nasty person
40. Giants
42. __ Farrow, actress
44. Area units
45. Noah's oldest son (Bible)
47. __ Lilly, drug company
49. Olfactory organ
50. Letter of the Greek alphabet
51. The 17th letter of the Greek alphabet