Definitions of strengthen

1. To make or become strong or stronger.

2. To make stronger; increase the power or security of; encourage.

3. To make strong or stronger: to confirm: to encourage: to increase in power or security.

4. To make strong; confirm; increase.

5. To become stronger.

6. To become strong or stronger.

7. give a healthy elasticity to; " Let's tone our muscles"

8. To make strong or stronger; to add strength to; as, to strengthen a limb, a bridge, an army; to strengthen an obligation; to strengthen authority.

9. To animate; to encourage; to fix in resolution.

10. To add strength to, either physical, legal or moral; to confirm; to animate; to cause to increase in power or security.

11. To add strength to; to grow stronger; to fix in resolution; to invigorate; to confirm.

12. Strengthener.