An angusticlavia, or angusticlavus, in ancient Rome, was a narrow purple strip as garment worn on Roman tunica, or tunic. The angusticlavia was worn by the eques, or knight.
The word is compounded of angustus ("narrow; small"), and clavus ("nail; stud"). This comes from the fact that those ornaments were narrower in this garment than in the laticlavus worn by senators.
This article incorporates content from the 1728 Cyclopaedia, a publication in the public domain.