posse comitatus

From Late Latin posse comitātūs (“force of the county”, literally “power of the county”).

posse comitatus

1. (historical) The able-bodied men over 15 in a given county who can be summoned by the sheriff to help keep the peace, or arrest a felon; also a group of men so gathered. [from early 17th c.]
   • 1849, Henry David Thoreau, Resistance to Civil Government:

     They are the standing army, and the militia, jailers, constables, posse comitatus, etc.

2. (figuratively) Any band of men, especially armed or hostile.
   • 1819, Lord Byron, Don Juan, section I:

     With him retired his ‘posse comitatus,’ / The attorney last, who linger'd near the door / Reluctantly […]

• posse

• “posse comitatus”, in Merriam-Webster Online Dictionary, Springfield, Mass.: Merriam-Webster, 1996–present.
• Douglas Harper (2001–2024) “posse”, in Online Etymology Dictionary.
• posse comitatus on Wikipedia.Wikipedia