PCS

*ˁḏr - to help (Hasselbach–Huehnergard 2007:420; Kogan 2015: 206)

Note that the semantic gap between the meaning “to excuse” in Arabic and “to help” reconstructed for PCS is considerable. See also Arb ˁuḏr- ‘attainment, accomplishing of what one wants, success, victory’. Does this derived noun preserve a more archaic meaning “success” (< “help”), lost elsewhere in Arabic? For the semantic relationship between “help” and “victory, success” cf. Arb. naṣr- (Kogan 2015: 206)

Akkadian
ḫāzirum - helper (AHw. 339, CAD Ḫ 166, Streck 2000:96)

OB Mari

Ugaritic
ˁḏr - to help (DUL 153)
Ugaritic
ˁḏrt - help (DUL 153)
Amarna Canaanite
ˁiḏirtu - help (Huehnergard 1996: 112)
i-zi-ir-tu (EA 87:13), i-zir-t[a] (EA 89:18), ḫi-zi-ir-ta (ZA 86, 101:34)
Phoenician
ˁzr - to help (DNWSI 836)
Hebrew
ˁzr - to help (HALOT 810)
Syriac
ˁdr - to help, aid (LSyr. 513, SL 1073)
Arabic
ˁḏr - to excuse, to free, to exempt from blame (Lane 1983)
Sabaic
ˁḏr, ḏ-ˁḏr, ḏ-ˀˁḏr - followers, adherents (SD 13)
Sabaic
s₁tˁḏr - to seek pardon (SD 13)
Qatabanian
ḏ-ˁḏr - protegé, dependent (LIQ 116)
Mehri
ˀāḏōr - to offer food (ML 13)
Mehri
hāḏōr - to excuse (ML 13)
borrowed from Arabic
Jibbali
ˁɔ́ḏɔ́r - to excuse (JL 7)
borrowed from Arabic