測

A phono-semantic compound:

水 (수) — semantic component, indicating liquid, water, depth

則 (칙/즉) — phonetic component, supplying the sound (측 / cè)

The original meaning was “to measure the depth of water”, a crucial practical task in navigation and irrigation.

From this concrete act of gauging depth, the meaning broadened to measurement in general, and further to estimation and inference.

Semantic development:

- water-depth measurement — sounding

- physical measurement — length, weight, quantity

- testing and probing — experimental measurement

- abstract estimation — prediction, inference

測 is widely used in scientific, technical, and analytical contexts.

Common compounds:

측정 (測定) — measurement

계측 (計測) — metering; instrumentation

관측 (觀測) — observation; monitoring

예측 (豫測) — prediction

측량 (測量) — surveying

측심 (測深) — sounding; depth measurement

Figurative usage:

심리를 측하다 — to gauge someone’s mind

의도를 측하기 어렵다 — intentions are hard to read

Unlike 量 (to measure quantity), 測 emphasizes methodical probing or gauging, often with uncertainty.

Related characters (measurement & estimation):

量 — quantity; measure

計 — calculate

算 — compute

察 — examine

探 — probe

Among these, 測 uniquely centers on gauging the unknown, bridging measurement and prediction.