From Sanskrit कृतज्ञ (kṛtajña, “to acknowledge what has been done”), a compound of कृत (kṛta, “done”) + ज्ञ (jña, “to know, acknowledge”).
কৃতজ্ঞ • (kŕtôggo) (comparative আরও কৃতজ্ঞ, superlative সবচেয়ে কৃতজ্ঞ)