claustra ōrum, n claudo, a lock, bar, bolt: revellere claustra: rumpere, V.: portarum, L.: sub claustris rei p. positum vectigal.

—A barrier, bounds: obstantia rumpere claustra (the barriers of a race - course), H.

— A gate, dam, dike: Lucrino addita, V.: portūs claustra, entrance, Cu.

— A barricade, bulwark, key, defence, fortress, wall, bank: ut terra claustra locorum teneret: urbs velut claustra Etruriae, L.: montium, passes, Ta.: Aegypti, the key to Egypt, L.: claustra contrahere, i. e. the line of circumvallation, Ta.

— A barrier, hinderance: ista nobilitatis.