Rask is a Norwegian word which means 'quick' or 'fast'. There are several synonyms for the word rask in the English language. Some of these synonyms include swift, rapid, fleet, speedy, expeditious, and brisk. All of these words convey a similar meaning to rask and can be used interchangeably depending on the context. For example, someone might describe a runner as swift or rapid, while a car might be described as fleet or speedy. Similarly, a person working efficiently might be described as expeditious or brisk. Using synonyms can help to add variety and nuance to writing and speech, making it more interesting and impactful.