What is Brevia Anticipantia?

Legal Definition
This name is given to a number of writs, which are also called writs of prevention. See Quia Ti. met.
-- Bouviers Law Dictionary
Legal Definition
At common law. Anticipating or preventive writs. Six were included in this category, viz.: Writ of mesne; toarrantia chartoe; monstraverunt; audita querela; curia claudenda; and ne injuste vexes. Peters v. Linen.-schmidt, 58 Mo. 466.
-- Black's Law Dictionary