By surface analysis, সত্য (śotto) + -ই (-i).
সত্যি • (śotti) (comparative আরও সত্যি, superlative সবচেয়ে সত্যি)
- true, genuine
- Subhasha Bhattacarya, Sailendra Biswas, Sailendra Biswas, and Jnanendramohana Dasa (2022) “সত্যি”, in Digital Dictionaries of South India [Combined Bengali Dictionaries]
- Accessible Dictionary, Bengali-English, সত্যি, Government of Bangladesh