Definition of twelve-incher in US English:

twelve-incher

(also 12-incher)

noun

  • Something that measures twelve inches in length, diameter, height, etc.; specifically (a) a cannon with a bore of twelve inches; (b) a twelve-inch record.

Origin

Early 20th century; earliest use found in ‘O. Henry’ (1862–1910), short-story writer (real name William Porter). From twelve + incher, after twelve-inch. Sometimes written with numerical symbol for the first element.

Pronunciation

twelve-incher

/ˌtwɛlvˈɪn(t)ʃə/