PurpleMagicCube zhanmadao is actually a horse chopping saber. https://en.m.wikipedia.org/wiki/Zhanmadao
In the Chinese language, dao refers to single edged swords while jian refers to double edged swords. In English, however, sabers are technically a subclass of swords and they are determined by the size/curvature. Since there is no precise term for dao, the translators in the community including those from WuxiaWorld have been using saber for dao and sword for jian.
With dao being a single edged blade, it means that even kitchen knives are being referred to as daos in Chinese. Hence, there is no precise translation for Zhanmadao other than its internationalized name, the Horse Chopping Saber, which is lengthy and not so cool as a proper noun for an MC's weapon.