From the triconsonantal root ع-د-ل (ʿ-d-l), conveying straightness and balance. This root yields a rich family: عَدْل (ʿadl, "justice"), عَادِل (ʿādil, "fair/just" — also a common male name), and مَعْدِل (maʿdil, "average/rate"). The root is shared across Semitic languages, appearing in Hebrew as עֶדֶל and Aramaic cognates, all circling the idea of setting something upright or straight.

عَدْل (justice), the noun from this root, is one of the 99 names of God in Islam (الْعَدْل, al-ʿAdl), making this root deeply embedded in Islamic theology and Arabic moral vocabulary. The concept is central to Islamic jurisprudence (فِقْه), and calling someone عَادِل is a high moral compliment. Be careful not to confuse عَدَلَ (to be just) with عَدَّلَ (ʿaddala, with shadda on the dāl), which means "to amend or modify" — a common false-friend trap for learners.