No. Arihant and Tirthankar (Trithankar) are related but not the same.

• Arihant: a soul who has conquered inner enemies (like anger, pride, deceit, greed) but has not yet attained complete omniscience. There are many Arihants across time.

• Tirthankar (Trithankar): a special kind of Arihant who has also attained kevala jnana (omniscience) and has established a Jain tirth. There are exactly 24 Tirthankaras in every cosmic cycle.

In short: all Tirthankaras are Arihants, but not all Arihants are Tirthankaras. The term Trithankar specifically refers to those 24 omniscient teachers. If you’d like, I can name the 24 Tirthankaras and their key roles.