To fit something with a motor.
Example: Most canoe aficionados would argue that motorizing a canoe removes the pleasurable aspects of traveling in one.
To supply something or someone with motor vehicles.
Example: Once Jack decided to motorize his paper delivery route, he found he could reach far more subscribers.
To supply armoured vehicles; to mechanize.
Example: The refit plan recommended that the first battalion be motorized to upgrade their offensive capabilities.