注射
zhùshè · HSK 5
injection
💉 注 = pour/inject + 射 = shoot; literally pour-shoot into the body
注 means to pour or pour-in (water radical 氵 + 主), and 射 means to shoot or fire. Together: pour-shoot, i.e. shoot fluid into the body — an injection. Same 注 as in 注意 (pour attention).
注 — water 氵 + master 主 (phonetic)
A semantic-phonetic compound: 氵 (water) gives the meaning of pouring or flowing, while 主 supplies the sound. The original sense was 'to pour water in,' which extended to 'concentrate, focus' (as in pouring attention) and 'to annotate' (pouring explanation into a text).
射 — body 身 + inch/hand 寸
Originally a pictograph of a hand drawing a bow with an arrow. The ancient form showed 弓 (bow) plus 矢 (arrow) or a hand. Over time it was reshaped into 身 (body) plus 寸 (hand/measure), and the meaning 'to shoot' was extended to 'emit' or 'project'.