Luck is our way of explaining the impossible, or improbable
such as,
Narrowly missing getting hit by a car -its like; how is that possible? I came
this close...boy am I lucky.
or, How did I hit that baseball? I was sure I was going to miss...I must be lucky.
Luck
explains the improbable.
Bad luck is the same, it also explains the improbable but in a more negative fashion.
such as
Damn! My tire blew out; I'm going to be late for work...It must be bad luck.
or, Damn! Out the hundreds of cars in the lot, the bird only shit on mine...my car must be bad luck.
Luck is what we use to answer for improbable events, the events that we will think never or are very unlikely to happen.
Thats what luck means