Definition of sack coat in English:

sack coat

noun

historical
  • A loose-fitting coat hanging straight down from the shoulders, particularly as worn by men (sometimes as part of military uniform) in the 19th and early 20th centuries.

    • ‘Additionally, do we really want the 'Campaigner community' to be clothed en masse in a sack coat style that less than 20% of the Federal Army wore?’
    • ‘The sack coat lacked the branch color trim that are found on the more formal frock coat or mounted man's jacket, and was much less costly for the government to produce.’