What is Armistice?

Legal Definition
An armistice is a formal agreement of warring parties to stop fighting. It is not necessarily the end of a war, since it may constitute only a cessation of hostilities while an attempt is made to negotiate a lasting peace. It is derived from the Latin arma, meaning "arms" (as in weapons) and -stitium, meaning "a stopping".

The United Nations Security Council often imposes, or tries to impose, cease-fire resolutions on parties in modern conflicts. Armistices are always negotiated between the parties themselves and are thus generally seen as more binding than non-mandatory UN cease-fire resolutions in modern international law.

An armistice is a modus vivendi and is not the same as a peace treaty, which may take months or even years to agree on. The 1953 Korean War Armistice Agreement is a major example of an armistice which has not been followed by a peace treaty. Armistice is also different from a truce or ceasefire, which refer to a temporary cessation of hostilities for an agreed limited time or within a limited area. A truce may be needed in order to negotiate an armistice.
-- Wikipedia
Legal Definition
A cessation of hostilities between belligerent nations for a considerable time. It is either partial and local, or general. It differs from a mere suspension of arms which takes place to enable the two armies to bury their dead, their chiefs to hold conferences or pourparlers, and the like. Vattel, Droit des Gens, liv. 3, c. 16, 233. The terms truce, (q. v.) and armistice, are sometimes used in the same sense. Vide Truce.
-- Bouviers Law Dictionary
Legal Definition
A suspending or cessation of hostilities between belligerent nations or forces for a considerable time.
-- Black's Law Dictionary
Legal Definition
An agreed interruption of hostilities between belligerent nations.
-- Ballentine's Law Dictionary