流す
ながす · nagasu · JLPT N3 · verb-godan
to shed
💧🚿 流 = flow; 流す nagasu = make it flow, the -su partner of 流れる nagareru
流れる (nagareru) means something flows on its own. Swap the ending for -su and you become the cause: you let water drain, set a boat floating downstream, or shed tears. Same pattern as 出る/出す (deru/dasu).
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'.