Definition of change-speed in US English:

change-speed

adjective

rare
  • Designating a gearing whose speed can be varied during operation, typically consisting of a set of differently sized gearwheels and a mechanism for switching between them, as "change-speed gear", "change-speed lever", "change-speed mechanism", etc.

noun

rare
  • A change-speed gear.

Origin

Late 19th century; earliest use found in Subject-matter Index Patents 1879.