Some important Antonyms in alphabetic order
1. Abandon - Support
2. Abide - Leave
3. Able - Incapable
4. Absent - Present
5. Abuse - Praise
6. Accurate - Inaccurate
7. Achieve - Fail
8. Active - Inactive
9. Addict - Detach
10. Admirable - Disgraceful
11. Admit - Deny
12. Advance - Retreat
13. Advantage - Disadvantage
14. Afraid - Fearless
15. Agree - Disagree
16. Aid - Hinder
17. Alive - Dead
18. Ally - Enemy
19. Always - Never
20. Ample - Scarce
21. Ancient - Modern
22. Answer - Question
23. Anticipate - Surprised
24. Apart - Together
25. Appear - Vanish
26. Approve – Disapprove
27. Artificial - Natural
28. Ascend - Descend
29. Ascertain - Guess
30. Attack - Defend
31. Attractive - Repulsive
32. Authentic - Counterfeit
33. Awake - Asleep
34. Awful - Wonderful
35. Awkward - Graceful
36. Back - Front
37. Bad - Good
38. Bargain - Overpay
39. Barren - Fertile
40. Beautiful - Hideous
41. Before - After
42. Begin - Finish
43. Below - Above
44. Beneficial - Harmful
45. Bent - Straight
46. Best - Worst
47. Better - Worse
48. Big - Small
49. Bind - Release
50. Bitter - Sweet
51. Blame - Praise
52. Blunt - Sharp
53. Bold - Timid
54. Borrow - Lend
55. Bottom - Top
56. Brave - Cowardly
57. Bright - Dim
58. Broad - Narrow
59. Build - Destroy
60. Busy - Idle
61. Buy - Sell
62. Calm - Agitated
63. Capture - Release
64. Careful - Careless
65. Cease - Continue
66. Cautious - Reckless
67. Cheap - Expensive
68. Cheerful - Sad
69. Clear - Unclear
70. Clumsy - Agile
71. Cold - Hot
72. Combine - Separate
73. Comfort - Discomfort
74. Common - Rare
75. Complete - Incomplete
76. Confident - Insecure
77. Connect - Disconnect
78. Construct - Demolish
79. Consume - Produce
80. Content - Discontent
81. Correct - Incorrect
82. Courageous - Fearful
83. Crawl - Run
84. Cruel - Kind
85. Cry - Laugh
86. Dangerous - Safe
87. Dark - Bright
88. Decrease - Increase
89. Defend - Attack
90. Deficient - Abundant
91. Delicate - Robust
92. Demand - Supply
93. Dense - Sparse
94. Depend - Rely
95. Despair - Hope
96. Destined - Random
97. Different - Similar
98. Difficult - Easy
99. Diminish - Enhance
100. Dirty - Clean