That which has to be done.

devoir - nm. (obligation) duty; faire quelque chose par devoir, to do something out of a sense of duty.
devoirs - (a la maison) homework; faire ses devoirs; to do one's homework.
devoir - v.aux. (indique obligation) devoir faire qch; to have to do something.
se devoir - vpr. je me dois a ma famille; I must devote myself to my family; je me dois de le faire; it's my duty to do it; comme il se doit; it is only right and proper.