Trouser/ˈtraʊzər/ Definition 1 of 3Pro Tip 1/3Clothing Term The word 'trouser' refers specifically to a type of garment. I need to buy new trousers for the event. Pro Tip 2/3Always Plural 'Trouser' is used in the plural form, even when referring to one pair. My trouser has a tear needs to be phrased as 'My trousers have a tear.' Pro Tip 3/3Category Specific The word can be preceded by an adjective to specify the type, like 'dress trousers.' He wore his formal trousers to the interview.