See also s.v. ארתך. The feminine concord (as well as that of the equivalent form ארתך in JPA) probably reflect that of the underlying Biblical Hebrew מֶרְכָּבָה . Page refs. in other dictionaries: Jastrow: 1503; Levy Ch-W: 2:441;
ˀrtk, ˀrtkˀ (ˀartaḵ, ˀartakkā) n.f. chariot(ry)