ف ر ضf-r-ḍ
(ض) فَرَضَ يَفْرِضُ فَرْضًاfaraḍa yafriḍu farḍan: the original sense is to make a notch or mark in something hard; hence (1) to appoint, to fix a share (2) to make obligatory, to ordain. ﴿اِنَّ الَّذِيْ فَرَضَ عَلَيْكَ الْقُرْاٰنَ لَرَآدُّكَ اِلٰى مَعَادٍ﴾ (Al-Qaṣaṣ 28:85)
فَرِيْضَةٌfarīḍah (on the pattern of فَعِيْلَةٌfaʿīlah, in the sense of a passive participle (ism mafʿūl)): an appointed share, an obligatory command. ﴿فَرِيْضَةً مِّنَ اللّٰهِ﴾ (An-Nisāʾ 4:11); مَفْرُوْضٌmafrūḍ (passive participle (ism mafʿūl)): appointed. ﴿نَصِيْبًا مَّفْرُوْضًا﴾ (An-Nisāʾ 4:118)
فَارِضٌfāriḍ (active participle (ism fāʿil)): old (of a cow), one whose share of life is complete. ﴿لَا فَارِضٌ وَّلَا بِكْرٌ﴾ (Al-Baqarah 2:68)