1. Shield
2. Protection
3. Safeguard
4. Safeness
5. Resistance
6. Security
7. Guard
8. Preserve
9. Cover
10. Shelter
11. Ward
12. Guarding
13. Bulwark
14. Screen
15. Shielding
16. Precaution
17. Immunity
18. Refuge
19. Sanctuary
20. Fortification
21. Wardship
22. Defense mechanism
23. Defending
24. Barricade
25. Rampart
26. Warding
27. Repel
28. Resisting
29. Prophylactic
30. Defensive

When looking for other words to describe defense, there are many options to choose from. Some of the best ideas for synonyms for defense include shield, protection, safeguard, safeness, resistance, security, guard, preserve, cover, shelter, ward, guarding, bulwark, screen, shielding, precaution, immunity, refuge, sanctuary, fortification, wardship, defense mechanism, defending, barricade, rampart, warding, repel, resisting, prophylactic, and defensive. Each of these words has a slightly different connotation and can be used to convey a different meaning when discussing defense. Using synonyms for defense can help to add clarity and nuance to conversations and writing.