in accompaniment or as a companion
"his little sister came along to the movies"
"I brought my camera along"
"working along with his father"
to a more advanced state
"the work is moving along"
"well along in their research"
"hurrying their education along"
"getting along in years"
in addition (usually followed by `with')
"we sent them food and some clothing went along in the package"
"along with the package came a bill"
"consider the advantages along with the disadvantages"
in line with a length or direction (often followed by `by' or `beside')
"pass the word along"
"ran along beside me"
"cottages along by the river"
In company; together.
"She walked along with her best friend to the park."
By the length of; in a line with the length of; lengthwise next to.
"The runner moved along the entire length of the track without stopping."
The word along comes from the combination of two Old English parts meaning "and" and "long." It originally described something extending in a long direction before evolving to mean moving forward or accompanying someone.