1.
to arrive; to appear :
When the right opportunity comes along, she'll take it.
2.
to go somewhere with sb :
I'm glad you came along.
3.
to improve or develop in the way that you want
SYN progress :
Your French has come along a lot recently.
4.
used in orders to tell sb to hurry, or to try harder :
Come along! We're late.
Come along! It's easy!