(ض) مَرٰى يَمْرِيْ مَرْيًاmarā yamrī maryan (original form: مَرَيَ يَمْرِيُmaraya yamriyu): to stroke (a she-camel's udder) to draw milk; thence to probe a matter out of doubt and to dispute. (This verb is not used in the Quran.)
مِرْيَةٌmiryah (noun, ism dhāt): doubt, uncertainty. ﴿فَلَا تَكُ فِيْ مِرْيَةٍ مِّنْهُ﴾ (Hūd 11:17)
Form III (mufāʿalah) مَارٰى يُمَارِيْ مِرَاءً وَمُمَارَاةًmārā yumārī mirāʾan wa-mumārātan: to dispute with one another out of doubt; لَا تُمَارِlā tumāri (prohibitive, nahy): do not dispute. ﴿اَفَتُمٰرُوْنَهُۥ عَلٰى مَا يَرٰى﴾ (An-Najm 53:12); ﴿فَلَا تُمَارِ فِيْهِمْ اِلَّا مِرَآءً ظَاهِرًا﴾ (Al-Kahf 18:22)
Form VI (tafāʿul) تَمَارٰى يَتَمَارٰى تَمَارِيًاtamārā yatamārā tamāriyan: to doubt and dispute with one another. ﴿فَبِاَيِّ اٰلَآءِ رَبِّكَ تَتَمَارٰى﴾ (An-Najm 53:55)
Form VIII (iftiʿāl) اِمْتَرٰى يَمْتَرِيْ اِمْتِرَاءًimtarā yamtarī imtirāʾan: to fall into doubt; مُمْتَرٍmumtar pl. مُمْتَرُوْنَmumtarūna (active participle, ism fāʿil): one who doubts. ﴿الَّذِيْ فِيْهِ يَمْتَرُوْنَ﴾ (Maryam 19:34); ﴿فَلَا تَكُوْنَنَّ مِنَ الْمُمْتَرِيْنَ﴾ (Al-Baqarah 2:147)