In Jain context, vajra means diamond-like or thunderbolt-like hardness and firmness. It is used to convey something extremely strong, unbreakable, and enduring.

In Jain literature, the word is often used symbolically to describe:

• great strength
• firm resolve
• unyielding purity
• steadfastness in dharma

So, vajra is not only a physical reference, but also a spiritual symbol of inner strength and firmness.