1. The 7th letter of the Greek alphabet.
4. An enclosed space.
7. An association of criminals.
11. A slight amount or degree of difference.
12. A dark-skinned member of a race of people living in Australia when Europeans arrived.
13. The chief solid component of mammalian urine.
14. The compass point that is one point east (clockwise) of due north.
15. A coenzyme derived from the B vitamin nicotinic acid.
16. United States publisher of magazines (1898-1967).
17. The branch of computer science that deal with writing computer programs that can solve problems creatively.
22. Title for a civil or military leader (especially in Turkey).
23. Large burrowing rodent of South and Central America.
25. A compartment in front of a motor vehicle where driver sits.
29. How long something has existed.
30. Having leaves or leaves as specified.
34. Plant with an elongated head of broad stalked leaves resembling celery.
37. The compass point midway between east and southeast.
41. An organization of countries formed in 1961 to agree on a common policy for the sale of petroleum.
42. A radioactive element of the actinide series.
43. Any of numerous local fertility and nature deities worshipped by ancient Semitic peoples.
45. Tag the base runner to get him out.
48. Electrical conduction through a gas in an applied electric field.
49. A constellation in the southern hemisphere near Telescopium and Norma.
50. A small cake leavened with yeast.
51. A nucleic acid that transmits genetic information from DNA to the cytoplasm.

1. An inactive volcano in Sicily.
2. A sock with a separation for the big toe.
3. A sweetened beverage of diluted fruit juice.
4. The capital and largest city of Yemen.
5. A loose sleeveless outer garment made from aba cloth.
6. Payment due by the recipient on delivery.
7. A Russian prison camp for political prisoners.
8. A popular island resort in the Netherlands Antilles.
9. The part of an organism that connects the head to the rest of the body.
10. (Greek mythology) Goddess of the earth and mother of Cronus and the Titans in ancient mythology.
18. The federal agency that insures residential mortgages.
19. A very young child (birth to 1 year) who has not yet begun to walk or talk.
20. (informal) Of the highest quality.
21. Date used in reckoning dates before the supposed year Christ was born.
24. A soft white precious univalent metallic element having the highest electrical and thermal conductivity of any metal.
26. A silvery ductile metallic element found primarily in bauxite.
27. A light strong brittle gray toxic bivalent metallic element.
28. A bachelor's degree in religion.
31. A public promotion of some product or service.
32. British informal term.
33. A long noosed rope used to catch animals.
34. Payment due by the recipient on delivery.
35. South American armadillo with three bands of bony plates.
36. Having nine hinged bands of bony plates.
38. Someone who works (or provides workers) during a strike.
39. An outlying farm building for storing grain or animal feed and housing farm animals.
40. Type genus of the Alcidae comprising solely the razorbill.
44. A river in north central Switzerland that runs northeast into the Rhine.
46. The blood group whose red cells carry both the A and B antigens.
47. An intensely radioactive metallic element that occurs in minute amounts in uranium ores.
48. A soft white precious univalent metallic element having the highest electrical and thermal conductivity of any metal.