4-2 Definition

noun
Under the Whyte notation system, a steam locomotive that has a four-wheel leading truck followed by a single driving axle.
Wiktionary
Under the Whyte notation system, a steam locomotive that has four leading wheels arranged in a leading truck, two driving wheels and two trailing wheels.
Wiktionary

(countable) Under the Whyte notation system, a steam locomotive that has a four-wheel leading truck, one powered driving axle and a four-wheel unpowered trailing truck.

Wiktionary

(soccer, uncountable) A popular soccer formation with 4 defenders, 2 midfielders and 4 strikers.

Wiktionary

Other Word Forms of 4-2

Noun

Singular:
4-2
Plural:
4-2-0s, 4-2-2s, 4-2-4s