by

1. 1.

   so as to pass a given point

   “every hour a train goes past”

   Synonymspast
2. 2.

   in reserve; not for immediate use

   “started setting aside money to buy a car”

   “put something by for her old age”

   “has a nest egg tucked away for a rainy day”

   Synonymsasideaway

Questions about by

What does by mean?

by means "so as to pass a given point". That is the primary sense; the word has 2 in total, listed in full on this page.