长度
chángdù · HSK 5
length
📏 长度 = long + degree → length / extent
长 means long, 度 means degree or measure. Together they form the abstract noun length — the measured extent of something long.
长 — pictograph of long-haired person with cane
Originally a pictograph showing a person with long, flowing hair leaning on a cane, representing an elder. The meaning extended from 'long hair' to 'long' in general, and also to 'elder' or 'to grow' (read zhǎng). The modern form 长 is a simplification of the traditional 長.
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.