(1) A practical compromise of arrangement that is acceptable to all concerned. (2) A way of life.
During the budget crisis, the Democratic governor and the Republican legislature established a modus vivendi that let them put aside their differences and tackle the problem at hand.
Modus vivendi literally means "manner of living" in Latin, and it sometimes has that meaning in English as well. Usually, though, a modus vivendi is a working arrangement that disputing parties can live with, at least until a more permanent solution can be found. Typically, a modus vivendi is an arrangement that ignores differences and difficulties. Two people going through a bitter divorce may be able to arrive at a modus vivendi that allows them to at least maintain an appearance of civility and dignity.