In Eng-lish law. A gathering of twelve persons or more, intending, going about, or practicing unlawfully and of their own authority to change any laws of the realm; or to destroy the inclosure of any park or ground inclosed, hanks of fish-ponds, pools, conduits, eic., to the intent the same shall remain void; or that they shall have way in any of the said grounds; or to destroy the deer in any park, fish in ponds, coneys in any warren, dove-houses, etc.; or to burn sacks of corn; or to abate rents or prices of victuals, etc. See Cowell
Source: Black's Law Dictionary 2nd Ed (1910)