Definition of red-short in US English:

red-short

noun

Founding
  • Iron or steel that is brittle when red-hot; the defect represented by this. Now rare.

adjective

Founding
  • Designating iron and steel that is brittle when red-hot, typically because of an excess of sulphur in the metal. Opposed to cold-short.

Origin

Mid 18th century; earliest use found in Beware of Bubbles. From red + short, perhaps after the adjectives Danish rødskør, † rødskjør or Swedish rödskör (although this is apparently first attested later: 1782).

Pronunciation

red-short

/ˌrɛdˈʃɔːt/