The noun luck has 3 senses (first 3 from tagged texts)
1. (8) fortune, destiny, fate, luck, lot, circumstances, portion -- (your overall circumstances or condition in life (including everything that happens to you); "whatever my fortune may be"; "deserved a better fate"; "has a happy lot"; "the luck of the Irish"; "a victim of circumstances"; "success that was her portion")
2. (6) luck, fortune, chance, hazard -- (an unknown and unpredictable phenomenon that causes an event to result one way rather than another; "bad luck caused his downfall"; "we ran into each other by pure chance")
3. (2) luck, fortune -- (an unknown and unpredictable phenomenon that leads to a favorable outcome; "it was my good luck to be there"; "they say luck is a lady"; "it was as if fortune guided his hand")