1. Electronic warfare undertaken under direct control of an operational commander to locate sources of radiated electromagnetic energy for the purpose of immediate threat recognition.
4. Little known Kamarupan languages.
8. The syllable naming the first (tonic) note of any major scale in solmization.
11. The month following March and preceding May.
12. A long fixed look.
13. Any of various primates with short tails or no tail at all.
14. Being one more than nine.
15. In bed.
16. Goddess of the dead and queen of the underworld.
17. Someone who works (or provides workers) during a strike.
19. In operation or operational.
21. On a ship, train, plane or other vehicle.
24. The capital and largest city of Yemen.
27. Wild sheep of semidesert regions in central Asia.
30. Top part of an apron.
31. A young woman making her debut into society.
33. A white metallic element that burns with a brilliant light.
34. A toxic nonmetallic element related to sulfur and tellurium.
35. A loose sleeveless outer garment made from aba cloth.
36. A medicinal drug used to evoke vomiting (especially in cases of drug overdose or poisoning).
41. (Babylonian) God of wisdom and agriculture and patron of scribes and schools.
45. A coral reef off the southern coast of Florida.
46. A sudden short attack.
49. The act of slowing down or falling behind.
50. The elementary stages of any subject (usually plural).
51. Very dark black.
52. United States liquid unit equal to 4 quarts or 3.785 liters.
53. Consisting of or made of wood of the oak tree.
54. Largest known toad species.
55. American prizefighter who won the world heavyweight championship three times (born in 1942).

1. Informal terms for a meal.
2. A detailed description of design criteria for a piece of work.
3. The template for protein synthesis.
4. Title for a civil or military leader (especially in Turkey).
5. Used as a Hindi courtesy title.
6. A chronic disease of the nose characterized by a foul-smelling nasal discharge and atrophy of nasal structures.
7. Having any of numerous bright or strong colors reminiscent of the color of blood or cherries or tomatoes or rubies.
8. Tropical woody herb with showy yellow flowers and flat pods.
9. An organization of countries formed in 1961 to agree on a common policy for the sale of petroleum.
10. Goddess of the dead and queen of the underworld.
18. The cry made by sheep.
20. Roman Emperor who was the adoptive son of Trajan.
22. Having undesirable or negative qualities.
23. An intensely radioactive metallic element that occurs in minute amounts in uranium ores.
25. The branch of computer science that deal with writing computer programs that can solve problems creatively.
26. A soft gray ductile metallic element used in alloys.
28. A radioactive element of the actinide series.
29. A white soft metallic element that tarnishes readily.
32. A soft silvery metallic element of the alkali earth group.
34. Being ten more than one hundred ninety.
37. A metabolic acid found in yeast and liver cells.
38. Flemish painter who was a founder of the Flemish school of painting and to have pioneered modern techniques of oil painting (1390-1441).
39. A particular geographical region of indefinite boundary (usually serving some special purpose or distinguished by its people or culture or geography).
40. Open-heart surgery in which the rib cage is opened and a section of a blood vessel is grafted from the aorta to the coronary artery to bypass the blocked section of the coronary artery and improve the blood supply to the heart.
41. School of Mahayana Buddhism asserting that enlightenment can come through meditation and intuition rather than faith.
42. Primitive chlorophyll-containing mainly aquatic eukaryotic organisms lacking true stems and roots and leaves.
43. Any of numerous local fertility and nature deities worshipped by ancient Semitic peoples.
44. Large sweet juicy hybrid between tangerine and grapefruit having a thick wrinkled skin.
47. An informal debt instrument.
48. A nucleic acid consisting of large molecules shaped like a double helix.