Something that flows out or forth; an emanation: "tremendous emotional effluences that affected blocks of people at a time, causing them to walk faster"(Coleman Dowell).
1603, from L.L. effluentia, from L. effluentem (nom. effluens) "flowing out," prp. of effluere "to flow out," from ex- "out" + fluere "to flow" (see fluent). Effluent (n.) "liquid industrial waste" is recorded from 1930.