A blazer is a type of jacket, usually double breasted although single breasted blazers have become more common recently. A blazer resembles a suit jacket except that it usually has patch pockets with no flaps, and metal shank buttons. A blazer's cloth is usually of a durable nature as it is used in schools and was used for sport.
They often form part of the uniform dress of bodies, such as airlines, schools, yacht or rowing clubs, and private security organizations. As sporting dress has become more adapted to the activity, the blazer has become more restricted to clubs' social meetings.
Commonly, blazers are navy blue, but almost every colour and combination of colours has been used, particularly by sporting organizations.
Several other folk etymology explanations are common. The name could derive from the traditional practice of attaching a school's, regiment's, club's, or ship's embroidered coat-of-arms to the breast of the coat - thus emblazoning the garment. Or the name may come from that of HMS Blazer, a frigate from the days when ratings supplied their own rigs or the captain did it for them if he wanted uniform dress. Blazer's captain, when faced with an inspection of his ship by Queen Victoria, decided to rig his boats' crews in short double breasted jackets in navy blue serge, with brass Royal Navy buttons on the model of the reefer worn by the midshipmen of his day. It seems that the Queen was duly impressed by the uniform and it became the style.
1885 Durham Univ. Jrnl. 21 Feb. 91 The latest novelty..for the river is flannels, a blazer, and spats.
1889 Daily News 22 Aug. 6/6 In your article of to-day..you speak of ‘a striped red and black blazer’, ‘the blazer’, also of ‘the pale toned’ ones... A blazer is the red flannel boating jacket worn by the Lady Margaret, St. John's College, Cambridge, Boat Club. When I was at Cambridge it meant that and nothing else. It seems from your article that a blazer now means a coloured flannel jacket, whether for cricket, tennis, boating, or seaside wear.