nounchiefly North American
A suit with a straight loose-fitting jacket.
More example sentences
- Brooks Brothers is credited with popularizing the ‘sack suit’.
- 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).
Definition of sack suit in:
- The US English dictionary