銳

A phono-semantic compound:

金 (“metal”) — semantic element, indicating relation to metal/weapon edges.

兌 (tae/ruì, “to exchange, phonetic”) — phonetic element.

Original meaning: the sharp point or edge of a blade or tool.

Extended senses: keen, acute, sharp-witted; vigorous, effective, eager, fierce.

鋭気 / 銳氣 (예기) — fighting spirit, vigor, morale

銳利 (예리) — sharp, keen, acute

銳敏 (예민) — sharp, sensitive, responsive

尖銳 (첨예) — pointed, acute, sharply defined

精銳 (정예) — elite, select, of outstanding quality

Common in military and political texts to denote elite troops (精銳) or sharp momentum (銳氣).

In modern East Asian usage, it appears both literally (sharp tools, blades) and metaphorically (sharp intellect, keen insight, acute criticism).