- to modify equipment (in airplanes, automobiles, a factory, etc.) that is already in service using parts developed or made available after the time of original manufacture.
- to install, fit, or adapt (a device or system) for use with something older: to retrofit solar heating to a poorly insulated house.
- (of new or modified parts, equipment, etc.) to fit into or onto existing equipment.
- to replace existing parts, equipment, etc., with updated parts or systems.
- something that has been retrofitted.
- an instance of updating, enlarging, etc., with new or modified equipment: A retrofit could save thousands of dollars.
- being or characterized by a retrofit: retrofit units.
- to equip (a vehicle, piece of equipment, etc) with new parts, safety devices, etc, after manufacture
