Constrictor /(?)/

Con·strict·or

Constrictor

n.
  1. That which constricts, draws together, or contracts.
  2. A muscle which contracts or closes an orifice, or which compresses an organ; a sphincter. (Anat.)
  3. A serpent that kills its prey by inclosing and crushing it with its folds; as, the boa constrictor. (Zool.)