流行
りゅうこう · ryuukou · JLPT N3 · noun
fad
🌊👗 流行 = flow + go: a style that flows through and goes everywhere
流 (ryuu) means current or flow, as in 電流, electric current. 行 (kou) means go, as in 旅行, travel. A fad is a current that sweeps through everyone and then moves on.
流 — water radical 氵 + 㐬 (phonetic, child being born)
流 is a semantic-phonetic compound. The water radical 氵 gives the meaning, while 㐬 depicts an infant being born head-down with amniotic fluid, suggesting downward flow. Together they convey water flowing, and by extension 'to flow' or 'current'.
行 — crossroads pictograph (left 彳 + right 亍)
行 originally pictured a four-way crossroads in oracle bone script, with two paths meeting. From 'road' it extended to 'walk, go, travel,' and then to 'a row, line' or 'business firm' (read háng). The two halves 彳 and 亍 are the split sides of that ancient crossroads.