v.
 make or become narrower, especially by encircling pressure. 
▸(of a snake) coil round (prey) in order to asphyxiate it.
 
  Derivative
  
    - constriction n.
  - constrictive adj.
 
   
  Etymology
  C18 (earlier (ME) as constriction): from L. constrict-, constringere (see constrain).