con|stric|tor «kuhn STRIHK tuhr», noun.
1. any snake that kills its prey by squeezing it with its coils. The boa, anaconda, and python are constrictors.
2. a person or thing that constricts: »
It has turned out to be an extraordinarily powerful bloodvessel constrictor (Harper's).
3. a muscle that constricts or narrows a part of the body: »
the constrictors of the eyelids.
Useful english dictionary. 2012.