Ace

Ace as in an expert fighter pilot, according to the OED, was coined in 1917 during the First World War, where an ace was any pilot credited with three enemy kills. Other sources give the minimum number of kills as five. The first recognised ace was a Frenchman, Adolphe Pegoud, who received the Croix de Guerre in 1915 for shooting down five German aircraft. French newspapers referred to him as an as, French for ace. Of course, some aces went on to record many more victories. For example, Manfred von Richthofen, the famous Red Baron and the top ace in WWI, was credited with 80 victories. The foremost Royal Flying Corps aces were Major Edward Mannock and Colonel William Bishop with 73 and 72 victories respectively. Very soon after WWI, an ace became an expert in any field, e.g. an ace at shooting, dancing, etc. An ace in tennis, where a player serves and wins the point without his or her opponent touching the ball, came into use during the 19th century. Ace, meaning a hole in one at golf is originally an Americanism and dates from the 1920s. Surprisingly, ace meaning, excellent or top class, through its association with the best or highest playing card, is not new at all. The word has been used in this way since the 18th century. See also come within an ace.