Definition of post line in US English:

post line

noun

rare
  • A postal route, especially in a terrain or region in which communication is difficult.

Origin

Late 18th century; earliest use found in George Washington (1732–1799), revolutionary army officer and president of the United States of America. From post + line.

Pronunciation

post line

/ˈpəʊs(t)lʌɪn/