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 four coupled leading wheels, twelve coupled driving wheels, and one pair of trailing wheels.

(US) A pencil which produces a specific shade of dark gray. One can usually identify a number 2 pencil by looking for the number "2" conspicuously emblazoned on the pencil. Often required for test-taking and the completion of official forms.

plural of 2-4-0

plural of 2-4-2

plural of 2-8-0

Under the Whyte notation system, a steam locomotive that has a single-axle leading truck followed by five powered driving axles, and no trailing wheels.

Under the Whyte notation system, a steam locomotive that has a single-axle leading truck followed by six powered driving axles, and no trailing wheels.

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

Under the Whyte notation system, a steam locomotive that has eight coupled driving wheels followed by two trailing wheels, with no leading wheels.