ذ ر عdh-r-ʿ
(ف) ذَرَعَ يَذْرَعُ ذَرْعًاdharaʿa yadhraʿu dharʿan: (1) to measure something by the dhirāʿ (the name of a unit of measure). (2) to come up from behind and strangle someone with the forearm; to weaken.
ذَرْعٌdharʿ (noun, ism dhāt): (1) measure, length. ﴿ذَرْعُهَا سَبْعُوْنَ ذِرَاعًا﴾ (Al-Ḥāqqah 69:32); (2) weakness, straitness (ضَاقَ بِهِۦ ذَرْعًاḍāqa bihi dharʿan = to become helpless). ﴿وَضَاقَ بِهِمْ ذَرْعًا﴾ (Hūd 11:77)
ذِرَاعٌdhirāʿ: (1) a unit of measure (the distance from the elbow to the tip of the middle finger); (2) the forearm, the arm. ﴿وَكَلْبُهُمْ بَاسِطٌ ذِرَاعَيْهِ بِالْوَصِيْدِ﴾ (Al-Kahf 18:18)