axe (ancient); jīn — a traditional unit of weight, about 500 g
Where it comes from
斤 first drew a simple hand tool: a stone or bronze adze with a wedge-shaped blade mounted on a handle, the everyday axe that felled trees and shaped timber. Because a chopped-off wedge of meat or metal was a natural, easy way to measure a fixed amount, the same character quietly slid from "axe" to a unit of weight — the jīn, still used to weigh vegetables and fruit at Chinese markets today.
A piece of culture
Half a jin, eight taels The jīn is still very much alive in China: one jīn equals 500 grams, and shoppers at wet markets ask for vegetables by the jīn every day. Older scales divided a jīn into 16 taels (两) rather than 10, which gave rise to the idiom 半斤八两 (bànjīn bāliǎng) — "half a jin, eight taels" — meaning two things are exactly equal, since half of sixteen is eight.
Use it in a real word
十斤
shíjīn · sap6 gan1
ten jin — about five kilograms; you already know 十