Answer

In Jain Dharma, arhat / arhant / arihaṅt are generally used for the same exalted being: a soul that has destroyed the inner enemies like attachment, anger, ego, deceit, greed, and has attained kevalajnana. A kevali is a soul with absolute omniscience. So, every arhat is a kevali, but the usage of the words is slightly different.

Explanation

1) Arhat / Arhant / Arihant

These are closely related forms and are commonly used for a Tirthankar or omniscient Jina while still living in the body.

Meaning:

• Arhat: a venerable, worthy one
• Arhant / Arihant: one who has destroyed inner enemies

In Jain usage, this word points to:

• complete destruction of karmas that hide true knowledge
• victory over passions
• worship-worthy spiritual greatness

2) Kevali

A kevali is a soul that has attained kevalajnana, meaning infinite, perfect knowledge.

There are two important points:

• A kevali is omniscient
• A kevali may still be embodied until the body falls away

So:

• Arhat / Arihant emphasizes the spiritual status and worshipful state
• Kevali emphasizes the omniscience

3) Simple difference

• Arhat / Arihant = the liberated-from-inner-enemies, worship-worthy omniscient being
• Kevali = the omniscient being

In practice, for a fully enlightened Jain soul, these terms overlap a lot.

Spiritual Understanding

In Jain Dharma:

• Arihant shows victory over passions
• Kevali shows perfect knowledge
• Both inspire us toward self-purification, right faith, right knowledge, and right conduct

The highest lesson is that the real enemy is not outside, but inside:

• anger
• pride
• deceit
• greed
• attachment
• aversion

Arihant represents complete inner conquest. Kevali represents complete illumination.

Takeaway

Short answer:

• Arhat / Arhant / Arihant = essentially the same in Jain usage
• Kevali = one who has attained absolute omniscience

So, an Arihant is a Kevali, but the word Arihant highlights victory over inner enemies, while Kevali highlights perfect knowledge.