ر د أr-d-ʾ
(ف) رَدَاَ يَرْدَاُ رَدْاًradaʾa yardaʾu radan: to help, to support, to prop up.
رِدْءٌridʾ (noun, ism dhāt): helper, supporter. Only once in the Quran, in the prayer of Mūsā (peace be upon him): ﴿فَاَرْسِلْهُ مَعِيَ رِدْاً يُّصَدِّقُنِيْٓ﴾ (Al-Qaṣaṣ 28:34) — i.e. send Hārūn as my helper.