CD

1. Cable Duct
2. Cadmium 
3. Cairo Damascus 
4. Call Data
5. Call Deflection
6. Call Detail
7. Call Disconnect
8. Call Distributor (PBX feature)
9. Canadian Forces Decoration
10. Candela 
11. Capability Data (ITU-T)
12. Carrier Detect
13. Carterfone Decision
14. cd (command)
15. Cell Delay (ATM)
16. Centre Democrats (Denmark)
17. Centro Democratico
18. Certificate of deposit
19. České Dráhy 
20. Chain Delivery (printing press)
21. Chained Declustering (computing)
22. Chromatic Dispersion
23. Circuit Description
24. Circuit Description (Bell System)
25. Circular dichroism
26. Civil Defense
27. Clock Distributor
28. Cluster of differentiation
29. Code Detector
30. Coeliac disease 
31. Coil Driver
32. Collision Detection
33. Color Display
34. Command Decoder
35. Commander of the Order of Distinction
36. Committee Draft
37. Common Dialog (windows programming)
38. Community of Democracies
39. Compact Disc
40. Compact Display
41. Companion dog
42. Completion Detector/Detection
43. Comprehensive Database
44. Computational Device
45. computer data
46. Computer Division (various locations)
47. Concept Definition
48. Conceptual Design
49. Conduct disorder
50. Conference on Disarmament
51. Connectivity Date
52. Conservation Dependent 
53. Context-Dependent (research parameter)
54. Contractual Data
55. Control and Display
56. Conventional Demodulation
57. Converter Drive
58. Coordinating Draft
59. Cordoba Durchmusterung,
60. CoreDirector (Ciena)
61. Corps Diplomatique
62. Cosmological decade 
63. Country Direct
64. Critical Defect
65. Current Density
66. Current Directory
67. Currently Disabled
68. Custom Delay
69. Democratic Republic of the Congo (country code, top level domain)
70.