交際
こうさい · kousai · JLPT N3 · noun
friendship
🤝 交 exchange + 際 edge/occasion = dealings where people meet
交 means exchange or mix (交流, 交換) and 際 means border or occasion (国際 = between nations). Together they mean social dealings between people. Also a hook on the sound: kousai, co-side, being side by side. Note: 交際中 often means dating.
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.