The word "泸定" is formed by combining the characters "泸" and "定", where "泸" is a phonetic-semantic character composed of the water radical (氵) denoting association with a river, specifically the Luzhou River, and the phonetic component "卢" indicating pronunciation, while "定" is a compound character formed from "宀" (roof) and "正" (upright) to mean settled or stable, so together they create a place name referring to a stabilized settlement near that river.