In simple terms, the answer to the raised question is- any men's clothing that is considered suitable to be worn on formal occasions like wedding, dinner parties and other social functions. Now what is meant by suitability? This can be thought of social acceptance of certain men garments. This can also mean a dress code or the rules stipulated for a combination of men's clothing keeping in view the formal national costumes. As such, mens formal wear ought to differ from region to region.
Western Men's Formal Wear!
The formal wear worn in western countries like US and Canada as well as in other countries like UK, Australia, New Zealand, and other Commonwealth countries include such men clothing as blazers, tuxedos, formal trousers, formal shirts, formal suits and the very popular waistcoats. In fact, Men's Waistcoat is not only one of the most popular men's formal wear but also a very important part of business suit.
Traditional Men's Formal Wear!
While the western formal wear is acceptable in almost all the countries of the world, there are certain traditional mens formal wear too for each country. Here is a list of traditional formal wear for men in some countries.