armistice

armistice \AHR-muh-stis\, noun:

A temporary suspension of hostilities by agreement of the warring parties.

Then one day, without warning, as though she, too, had accepted the armistice and the capitulation, the grandmother departed to visit her son in Mills City.
-- William Faulkner, Elly

Bill had eaten at the restaurant in 1918, and right after the armistice, and Madame Lecomte made a great fuss over seeing him.
-- Ernest Hemingway, The Sun Also Rises

Armistice is a Latin compound created by 17th century scholars. The Latin arma-, "arms," combines with sistere, "to be still."