Definition of "constrictor"

That which constricts or tightens:

1. (anatomy) A muscle whose contraction narrows a vessel or passage or compresses an organ.

   1. (anatomy) Each of the muscles which constrict the pharynx; ellipsis of pharyngeal constrictor..  examples

2. Ellipsis of boa constrictor.: a python or similar snake that kills by constriction.  examples