Boa

n. pl. Boas.
  1. (Zoöl.) A genus of large American serpents, including the boa constrictor, the emperor boa of Mexico (Boa imperator), and the chevalier boa of Peru (Boa eques).
  2. A long, round fur tippet; -- so called from its resemblance in shape to the boa constrictor.

The name is also applied to related genera; as, the dog-headed boa (Xiphosoma caninum).