in antiquity, an ornament upon the robes of the Roman senators and knights; which was more or less broad, according to the dignity of the person: hence the distinction of tunica angusti-clavia and lati-clavia.

medicine and surgery, is used in several significations: 1. Clavus hystericus, is a shooting pain in the head, between the pericranium and cranium, which affect such as have the green-fickness. 2. Clavus oculorum, according to Celsus, is a callous tubercle on the white of the eye, taking its denomination from its figure. 3. Clavus imports indurated tubercles of the uterus. 4. It also imports a surgical instrument of gold, mentioned by Amatus Lufitanus, designed to be introduced into an ulcerated palate, for the better articulation of the voice. And, 5. It signifies a callus, or corn on the foot.

Clavus Annalis, in antiquity. So rude and ignorant were the Romans towards the rise of their state, that the driving or fixing a nail was the only method they had of keeping a register of time; for which reason it was called clavus annalis. There was an ancient law, ordaining the chief pretor to fix a nail every year on the Ides of September; it was driven into the right side of the temple of Jupiter Opt. Max. towards Minerva's temple. This custom of keeping an account of time by means of fixing nails, was not peculiar to the Romans; for the Etrurians used likewise to drive nails into the temple of their goddess Nortia with the same view.