mid-15c., from Latin effluentem (nominative effluens) "flowing out," present participle of effluere "to flow out," from assimilated form of ex "out" (see ex-) + fluere "to flow" (see fluent). As a noun, "that which flows out," from 1859; specific meaning "liquid industrial waste" is from 1930.
effleurage
effloresce
efflorescence
efflorescent
effluence
effluent
effluvia
effluvium
efflux
effort
effortless