(~s)
1.
A ~ is the distance that light travels in a year.
...a star system millions of ~s away.
N-COUNT
2.
You can say that two things are ~s apart to emphasize a very great difference or a very long distance or period of time between them. (INFORMAL)
She says the French education system is ~s ahead of the English one...
N-COUNT: usu pl, N prep/adv emphasis