(vision) Synonym of 20/20.

MI6; the agency or a particular agent.

(military) Intruder twin engine low-altitude attack aircraft. / (military) Communications section of an Air Force staff.

Under the Whyte notation system, an articulated locomotive with two leading wheels on a leading truck, two sets of six driving wheels, and six trailing wheels on a trailing truck. This arrangement was used only on the C&O which called it the Allegheny and the Virginian, which named it the Blue Ridge.

Under the Whyte notation system, a steam locomotive that has two leading wheels, six coupled driving wheels, and six trailing wheels.

Under the Whyte notation system, a steam locomotive that has six leading wheels arranged in a leading truck, eight coupled driving wheels and six trailing wheels in a trailing truck.

Under the Whyte notation system, a duplex steam locomotive that has six coupled leading wheels in a leading truck, two sets of four driving wheels, and a six coupled trailing wheels in a trailing truck.

Under the Whyte notation system, a Mallet-type locomotive with two leading wheels on a leading truck, two sets of six driving wheels, and two trailing wheels on a trailing truck.

Under the Whyte notation system, a Mallet-type locomotive with no leading truck, two sets of six driving wheels, and no trailing truck.

Under the Whyte notation system, a Mallet-type locomotive with four leading wheels on a leading truck, two sets of six driving wheels, and two trailing wheels on a trailing truck.