卡子
qiǎ zi · HSK 7
clip
📎 卡 = clip/wedge + 子 = noun suffix; a thing that pinches shut
卡 (qiǎ) means to wedge or pinch tight, and 子 is a common noun suffix, so 卡子 is the little thing that clamps onto something. The same 卡 gives the checkpoint sense: a spot where you get pinched and stopped.
卡 — 上 (up) + 下 (down)
卡 is a modern compound formed by stacking 上 'up' on 下 'down', visually depicting something stuck between two positions — neither up nor down. From this 'wedged' image come its core meanings: to block, to get stuck, and a checkpoint or card. The reading kǎ also transcribes foreign words like 'card', while qiǎ keeps the older 'pinch/stuck' sense.
子 — pictograph of a baby/child with arms out
子 began as a pictograph of a swaddled infant with a large head and outstretched arms, originally meaning 'baby' or 'child.' From there it broadened to 'son,' 'offspring,' and a respectful suffix for masters like 孔子 (Confucius). It also became one of the twelve earthly branches.