sump

(n) an oil reservoir in an internal combustion engine
(n) a well or other hole in which water has collected
(n) a covered cistern; waste water and sewage flow into it cesspit, cesspool, sink,

cesspit cesspool sink

sumo

sub Sue sum sun sup Sur Sus S.U.V. SUV

such suck suds suer suet Suez Sufi sugi suit Sula sulk sumo Sung sunk sura surd sure surf Susa Suva

sump pump sumpsimus sumpter sumptuary sumptuosity sumptuous sumptuously sumptuousness