暗渠[ankyo] subterranean drain
渠魁[kyokai] ringleader
溝渠[koukyo] ditch
出渠[shukkyo] leaving the (repair) dock
入渠[nyuukyo] entering a dock

函渠[kankyo] drain with an oblong cross-section
乾船渠[kansenkyo] dry dock
船渠[senkyo] dock
暗渠排水[ankyohaisui] underdrainage
合流渠[gouryuukyo] combined sewer

レコードの溝[rekoodonomizo] record groove
下水溝[gesuikou] drainage ditch
海溝[kaikou] ocean trench
溝渠[koukyo] ditch
溝鼠[dobunezumi] brown rat (Rattus norvegicus)

畝溝[unemizo] furrow ridges
側溝[sokkou] gutter
排水溝[haisuikou] drainage
蘆溝橋[rokoukyou] Marco Polo Bridge (China)