Three"-port`, a. Having three ports; specif.: Designating a type of two-cycle internal-combustion engine in which the mixture enters the crank case through a port uncovered by the piston near the end of its stroke.

Three"-port`, a. Having three ports; specif.: Designating a type of two-cycle internal-combustion engine in which the mixture enters the crank case through a port uncovered by the piston near the end of its stroke.