Initialism of all-terrain vehicle.

• A straddle-seat off-road quad or tri-wheeled recreational vehicle.

Initialism of Automated Transfer Vehicle.

• European cargo spacecraft for resupplying the ISS.

Initialism of amateur television.

• Video transmission in the amateur radio service.

Initialism of airport transit visa.

• Visa permitting airside transfer without entering the country.

Abbreviation of atazanavir.

• An antiretroviral drug for HIV treatment.