- Cattle pen - A pen for animals; esp., an inclosure made with wagons, by
emigrants in the vicinity of hostile Indians, as a place of security
for horses, cattle, etc. - To surround and inclose; to coop up; to put into an
inclosed space; -- primarily used with reference to securing horses and
cattle in an inclosure of wagons while traversing the plains, but in
the Southwestern United States now colloquially applied to the
capturing, securing, or penning of anything.