What is Luck ?
Luck is (noun) something, usually good, which happens to you The bus is empty – that’s a bit of luck! good luck with your driving test! I hope you do well in your driving test I wear this ring for luck because I hope it will bring me luck bad luck!, hard luck! I am sorry you didn’t do well You failed the driving test again? – Bad luck! to be down on your luck to be going through a period of bad luck He was down on his luck and thought of emigrating. as luck would have it as it happened As luck would have it, the bus was empty.
source: Easier English, Student Dictionary Upper Intermediate Level