A copper coin worth a quarter of an as. This was really small change. The plural is "quadrantes."

The Roman 4th part of the bronze "AS."

The quadrans (literally meaning "a quarter") was a low-value Roman bronze coin worth 1/4th of an as. The quadrans was issued from the beginning of cast bronze coins during the Roman Republic with three pellets (representing three unciae) as a mark of value. The obverse type, after some early variations, featured the bust of Hercules, while the reverse featured the prow of a galley.