I recently learned about a language caled Sentinelese. Is there any word that somebody learned from those people? Is there any known word from the langauge?

Considering that the Sentinelese people are fiercely against outside intrusion (they kill most who land on their island and fire arrows at passing aircraft), no, I doubt that any will be gathered soon, either. Though I can guess it is like Bo, or other Andaman Island Languages.