A modern convenience.

A kind of gate or portcullis, having iron bars, like a harrow, studded with iron spikes, hung above gateways so that it may be quickly lowered to impede the advance of an enemy.

(zoology) Belonging to the Volvocaceae.

Of or relating to John Brown (doctor) (1735–1788), Scottish physician who taught that disease was caused by either excessive or inadequate stimulation.