• (n.) A narrow stripe of purple worn by the equites on each side of the tunic as a sign of rank.
An·gus'ti·clave (ăn*gŭs'tĭ*klāv) noun [ Latin angustus narrow + clavus a nail, a stripe.] (Rom. Antiq.) A narrow stripe of purple worn by the equites on each side of the tunic as a sign of rank. 
Angusticlave A narrow stripe of purple worn by the equites on each side of the tunic as a sign of rank (from Latin angustus, 'narrow' + clavus, 'a nail, a stripe'; Roman antiquity).