The Chinese word **轨迹 (guǐjì)** is a compound formed through semantic combination, where both characters contribute related meanings to create an abstract noun. The first character, **轨 (guǐ)**, originally means the tracks or grooves left by a wheel, extending metaphorically to a prescribed path or course. The second character, **迹 (jì)**, means a mark, trace, or footprint. When combined, they form a term that literally translates to "track marks" or "path traces," which evolved to denote the **locus or trajectory** of a moving point—the continuous path described by an object in space, a concept central to geometry and physics. Thus, the word exemplifies how Chinese often constructs abstract terminology by pairing concrete, visual characters to express a unified, more complex idea.