Plain English Meaning
Fly this heading on the chart until you are a set number of miles from a named ground station, then the leg is over and the next instruction begins.
Full Definition
A path-and-terminator (path terminator) leg type used in coded instrument procedures in which the aircraft flies a specified course until it reaches a defined DME distance from a referenced navigation aid. The leg is defined by two elements: the course to be flown and the DME distance from a specific station that ends (terminates) the leg.
Context Anchor
Seen in instrument procedure design and navigation database descriptions for path and terminator legs.