slave

[1]	labour , toil , moil , grind , grub , drudge , sweat , burn the midnight oil , lucubrate , work one's fingers to the bone , work like a Trojan/a horse , (Brit) skivvy
[2]	break one's back , buckle down , knuckle down

[1]	lackey/lacquey , scullion , serf , slave-girl , slaveling , odalisque/odalisk , bondservant , bondslave , bondsman/bondman , bondswoman/bondwoman , bondmaid , vassal , (Derogatory) (Mainly Brit) skivvy , (Archaic) esne , helot , hierodule , (Colloq) (Brit) slavey
[2]	drudge , striver , hard worker , workhorse , hack , grind , toiler , labourer , (Mainly Brit) fag , dogsbody , (Colloq) (US) gofer