交換
こうかん · koukan · JLPT N3 · noun
exchange
🥫🔁 交 cross + 換 replace = swap; koukan sounds like coke can, traded hand to hand
交 means to cross or mix, as in 交差 (crossing). 換 means to replace, as in 換気 (ventilation: air swapped out). Things cross between two people and each gets a replacement. Hook: you swap your coke can (koukan) for a friend's.
交 — top 亠 + 父-like crossed legs
Originally a pictograph of a person standing with legs crossed, showing the idea of crossing or intersecting. From this concrete image, the meaning extended to abstract senses like 'exchange,' 'interact,' and 'hand over.' Modern uses such as 交流 (exchange) and 交通 (traffic) all trace back to this core notion of crossing.