奴隷 is read as どれい (dorei) and means slavery.
どれい
dorei
どれいせいどはいし
abolition of slavery
どれいかいほうせんげん
Emancipation Proclamation (1863)
どれいせいど
(system of) slavery
どれいしょうにん
slaver
どれいかいほう
emancipation of slaves
どれいこんじょう
servile character (disposition)
どれいけいやく
slave contract (in the entertainment industry)
どれいろうどう
slave labor
どれいせい
どれいおうちょう
Slave dynasty (of India; 1206-1290)
どれいせん
slave ship
どれいぼうえき
slave trade