Where does “Lan Xang” come from?

Lan Xang (Vietnamese) comes from Lao ລ້ານຊ້າງ, from Lao ຊ້າງ, from Proto-Tai *ɟaːŋꟲ, from Middle Chinese 象, from Old Chinese 象 — elephant.

Lan Xang (Vietnamese): Lan Xang, a former Laotian kingdom