CMV
Commercial motor vehicle (CMV) means a motor vehicle that has any of the following characteristics:
(1) A gross vehicle weight (GVW), gross vehicle weight rating (GVWR), gross combination weight (GCW), or gross combination weight rating (GCWR) of 4,537 kilograms (10,001 pounds) or more.
(2) Regardless of weight, is designed or used to transport 16 or more passengers, including the driver.
(3) Regardless of weight, is used in the transportation of hazardous materials and is required to be placarded pursuant to 49 CFR part 172, subpart F.
Source
49 CFR § 350.105
Scoping language
Unless specifically defined in this section, terms used in this part are subject to the definitions in 49 CFR part 390. As used in this part: