Formal/ˈfɔːrml/ Definition 1 of 4Pro Tip 1/3Dress Code Used when specific, upscale clothing is expected or required for an event. A formal suit is mandatory for the gala. Pro Tip 2/3Not Casual Indicates something is not casual or relaxed, and there's an elevated level of seriousness. Please switch to a formal tone for this meeting. Pro Tip 3/3Tradition Highlights adherence to traditional customs or established norms. The formal proceedings of the court are steeped in tradition.