卡片
kǎpiàn · HSK 7
card
🃏 卡 ka = loanword from card + 片 pian = flat slice/piece
卡 was borrowed for the English sound of card; 片 means a thin flat piece (also in 照片 photo). Together a flat card. 卡 also shows up in 卡车 truck and 卡通 cartoon, all sound-loans.
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.
片 — right half of 木 (tree split vertically)
Pictograph showing the right half of a tree 木 split down the middle, depicting a thin slice or slab of wood. From this came the meanings 'slice,' 'flat thin piece,' and by extension 'sheet' or 'card.' Its mirror image 爿 represents the left half.