ط م ا نṭ-m-ʾ-n
(quadriliteral, rubāʿī) طَمْاَنَ يُطَمْئِنُ طَمْاَنَةًṭamʾana yuṭamʾinu ṭamʾanatan: to set at ease. (اِفْعِلَّالifʿillāl) اِطْمَاَنَّ يَطْمَئِنُّ اِطْمِئْنَانًاiṭmaʾanna yaṭmaʾinnu iṭmiʾnānan: to become at ease.
مُطْمَئِنٌّmuṭmaʾinn (active participle, ism fāʿil): at ease, tranquil. ﴿اَلَا بِذِكْرِ اللّٰهِ تَطْمَئِنُّ الْقُلُوْبُ﴾ (Ar-Raʿd 13:28); ﴿وَلٰكِنْ لِّيَطْمَئِنَّ قَلْبِيْ﴾ (Al-Baqarah 2:260); ﴿يٰٓاَيَّتُهَا النَّفْسُ الْمُطْمَئِنَّةُ﴾ (Al-Fajr 89:27) (see ṭ m n)