Tra từ lounge suit - Từ điển Oxford Advanced Learner 8th

ˈlounge suit f11 BrE NAmE noun (BrE)
a man's suit of matching jacket and trousers/pants, worn especially in offices and on fairly formal occasions

Culture:
formal and informal dress [formal and informal dress lounge suit]
In general, people in Britain and the US dress fairly informally. Many wear casual clothes most of the time, not just when they are at home or on holiday. Men and women wear ↑jeans or cords (= corduroy trousers) with a shirt or T-shirt and a sweater to go shopping, meet friends, go to a pub or bar, or take their children out. Older people are more likely to dress more smartly, with women wearing a dress or skirt and blouse, and men a shirt, jacket and trousers, when they go out. In summer younger people may wear shorts (= short trousers/pants), but some people think they are only appropriate on the beach.
Most people dress up (= put on smart clothes) to go to a party or club. Some restaurants will not let in people who are wearing jeans. Most people do not now dress up to go to the theatre. Young people are most interested in following ↑fashion and regularly buy new clothes.
Men wear lounge suits, and women wear suits or dresses, for formal occasions like funerals or interviews for jobs. Some wear suits or smart clothes every day because their employer expects it or because they think it makes them look more professional. In London many people who work in the City wear pinstripe suits made of dark cloth with narrow grey vertical lines. Most people prefer casual, comfortable clothes for work but some companies do not like people wearing jeans. Employees in banks and shops often have uniforms.
For formal occasions during the day, such as a wedding, men may wear morning dress. This includes a jacket with long ‘tails’ at the back, dark grey trousers and a grey top hat. Women wear a smart dress and often a hat. For very formal events in the evening, men may wear evening dress, also called white tie, which consists of a black tailcoat, black trousers, a white waistcoat, white shirt and white bow tie. Women usually wear a long evening dress or ball gown. Usually for formal evening events men wear black tie/tuxedo, consisting of a black dinner jacket, black trousers and a black bow tie.