沿线
yán xiàn · HSK 7
along the line
🛤️ 沿 (along) + 线 (line/thread) = the area running along a line, like a rail route
沿 — water 氵 + 㕣 (marsh/valley) phonetic
沿 combines the water radical 氵 with 㕣, depicting a stream flowing through a small valley. Originally it meant to follow along the course of a river, and by extension came to mean 'to follow,' 'along,' or 'beside.' The 㕣 element also gives the sound.
线 — silk radical 纟 + 戋 (jiān, phonetic)
线 is a semantic-phonetic compound. The silk radical 纟 signals the meaning 'thread' or 'string,' while 戋 hints at the sound. Originally referring to silk thread, its meaning broadened to any thin line, wire, or route. The traditional form is 線.