The usually constricted communicating column between the head and trunk of the vertebrate body.

The part of a furnace where the flame is contracted before reaching the stack.

A narrow strip of land, especially one connecting two larger areas.

See <<pipe>>

In a tensile test, that portion of the metal at which fracture is imminent during the later stages of plastic deformation in a tensile test.

The narrow band of water forming the part of a rip current where feeder currents converge and flow swiftly through the incoming breakers and out to the head.