Friday/ˈfraɪdeɪ/ Definition 1 of 3Pro Tip 1/3Weekend Start In many cultures, Friday marks the beginning of the weekend. Susan loves Fridays because it means the workweek is over. Pro Tip 2/3Casual Day Some workplaces have 'Casual Friday' where you can dress more informally. Don't wear your suit this time; it's Casual Friday tomorrow. Pro Tip 3/3Social Activities Friday night is often used for social gatherings and entertainment. Are you free on Friday night for a movie?