The phrase "blue blazer" refers to a classic item of clothing mostly worn by men. It generally refers to a navy blue, single-breasted jacket with brass buttons. However, there are several synonyms for the term, including sports coat, sport jacket, blazer jacket, and dress jacket. All of these variations share a similar design and are typically worn for dressier occasions. While the navy blue color with brass buttons may be the most common option for a blue blazer, there are also other color options available, including gray, black, and dark green. Overall, the blue blazer remains a staple in men's fashion and is a versatile piece that can be dressed up or down.