This is the 353rd most frequent Tamil word.
இழந
The word "இழந" seems to be a typo or incomplete. If you meant "இழந்த," it translates to "lost" in English.
The word "இழந்துவிட்டேன்" translates to "lost" and is derived from "இழந" to denote something that was lost.
நான் என் கைப்பையை இழந்துவிட்டேன்.
I lost my bag.
In this sentence, "இழந்தான்" means "lost" and signifies the act of losing a job, derived from "இழந."
அவன் வேலை இழந்தான்.
He lost his job.
Here, "இழந்தோம்" means "lost" and is used in the context of failing in a competition, again derived from "இழந."