Definition of sack suit in English:

sack suit

noun

North American
  • A suit with a straight loose-fitting jacket.

    • ‘The lion had his mane, the peacock his gorgeous plumage, but Man found himself in a three-button sack suit.’
    • ‘Even in a sack suit or standard blazer, it's a good idea to get the jacket one size large (in the body, not the sleeves).’
    • ‘Brooks Brothers is credited with popularizing the ‘sack suit’.’
    • ‘I've found wearing a sack suit in business situations, including interviews, to be a no-lose situation.’
    • ‘The classic American men's sack suit popularized by Brooks Brothers and Hart, Schaffner & Marx conceals a gun the size of a snubnose .38 in a front pocket.’