経度
けいど · keido · JLPT N2 · noun
longitude
🌐 经 = warp threads + 度 = degree: longitude lines run north-south like warp
经 originally meant the lengthwise threads on a loom. Longitude lines run north-south, parallel like those threads, and 度 is the unit of angle.
度 — 广 (shelter) + 庶 abbreviated (phonetic)
Originally depicted a hand measuring length under a shelter, meaning 'to measure' or 'a measure/standard.' From this came extended senses like 'degree,' 'extent,' and 'to pass through' (as in passing time). The reading 'dù' means degree/measure, while 'duó' preserves the older verbal sense of measuring.