The meaning of luck according to Wikipedia

Luck or fortuity is good or bad fortune in life caused by accident or chance, and attributed by some to reasons of faith or superstition, which happens beyond a person’s control. The term “luck” is pervasive in common speech. There are at least two senses people usually mean when they use the term, the proscriptive sense and the descriptive sense. In a proscriptive sense, luck is the deterministic concept that there is a force which proscribes that certain events occur very much the way the laws of physics will proscribe that certain events occur. In a descriptive sense, luck is only a descriptive name we give to events after they occur which we find to be fortuitous. Cultural views of luck vary from perceiving luck as a matter of random chance to attributing to luck explanations of faith or superstition. For example, the Romans believed in the embodiment of luck as the goddess Fortuna, while the atheist and philosopher Daniel Dennett believes that “luck is mere luck” rather than a property of a person or thing. Lucky symbols have widespread global appeal and are represented by human, animal, botanical and inanimate objects. (http://en.wikipedia.org/wiki/Luck)