sewer

n. 排水沟，下水道

seven-, seven-course, seventeen, seventeenth, seventh, seventieth, seventy, seventy-eight, sever, several, severally, severance, severance pay, severe, severely, severity, sew, sewage, sewage farm, sewage works, sewerage, sewing, sewing-machine, sewn, sex, sex act, sex appeal, sex life, sex-, sex-starved, sexagenarian, sexily, sexiness, sexism, sexist, sexless, sexologist, sexology, sextant, sextet (also sextette),