Definition of big inch in US English:

big inch

adjective

North American
  • Of an oil or natural gas pipeline: having a large diameter.

noun

North American
  • 1With the and capital initials. A large-diameter oil pipeline running from the Texas oilfields to the industrial north-east of the United States, laid during the Second World War (1939–45).

  • 2Generally. A large-diameter pipeline for oil or natural gas.

Origin

1940s; earliest use found in Excavating Engineer. From big + inch.

Pronunciation

big inch

/ˌbɪɡ ˈɪn(t)ʃ/