Stipulation
WordNet
noun
(1) A restriction that is insisted upon as a condition for an agreement
(2) An assumption on which rests the validity or effect of something else
(3) (law) an agreement or concession made by parties in a judicial proceeding (or by their attorneys) relating to the business before the court; must be in writing unless they are part of the court record
"A stipulation of fact was made in order to avoid delay"
WiktionaryText
Etymology
From ancient . As was the custom then, the Romans used to break a straw, as a sign of agreement between the negotiating parties, and the stipulations were put in a written form.