What is Admittendo In Socium?

Legal Definition
A writ for associating certain persons, as knights and other gentlemen of the county, to justices of assize on the circuit Reg. Orig 206.
-- Black's Law Dictionary
Legal Definition
Eng. law. A writ associating certain persons to justices of assize.
-- Bouviers Law Dictionary
Legal Definition
A writ associating certain persons to justices of assize.
-- Ballentine's Law Dictionary