narrow gauge

English Thesaurus

1. a railroad track (or its width) narrower than the standard 56.5 inches (noun.artifact)

hypernym	:	railroad, railroad track, railway,
definition	:	a line of track providing a runway for wheels (noun.artifact)

hypernym	:	gauge,
definition	:	the distance between the rails of a railway or between the wheels of a train (noun.attribute)