An aptitude is an innate talent or combination of talents that give you a natural ability to perform a specific function readily, naturally, easily. It is a knack, a gift, not an acquired skill or an achievement. Sometimes it is a single talent such as physical coordination or analytical reasoning. Often it is a combination of talents that, like instruments in a band, play together in harmony. An aptitude for surgery or basketball both involve the complex interplay of several innate abilities which are then brought to fruition through extensive training.