Antonyms:
1. Happy - Sad
2. Hot - Cold
3. Big - Small
4. Light - Dark
5. Strong - Weak
6. Fast - Slow
7. Up - Down
8. Good - Bad
9. Right - Wrong
10. Open - Closed
11. Clean - Dirty
12. New - Old
13. Busy - Idle
14. Wet - Dry
15. Quiet - Loud
16. Smooth - Rough
17. Kind - Cruel
18. Brave - Cowardly
19. Generous - Stingy
20. Honest - Dishonest
Synonyms:
1. Happy - Joyful, cheerful, delighted
2. Hot - Scorching, boiling, sweltering
3. Big - Large, huge, enormous
4. Light - Bright, luminous, radiant
5. Strong - Powerful, sturdy, robust
6. Fast - Swift, rapid, speedy
7. Good - Excellent, wonderful, superb
8. Right - Correct, accurate, proper
9. Clean - Spotless, pristine, immaculate
10. New - Fresh, recent, modern
11. Busy - Active, occupied, engaged
12. Wet - Damp, moist, soggy
13. Quiet - Silent, peaceful, tranquil
14. Smooth - Slick, polished, silky
15. Kind - Compassionate, caring, gentle
16. Brave - Courageous, valiant, fearless
17. Generous - Charitable, philanthropic, bountiful
18. Honest - Truthful, sincere, upright
19. Beautiful - Lovely, gorgeous, stunning
20. Important - Significant, crucial, vital