|1.||over or for the length of, esp in a more or less horizontal plane: along the road|
|2.||continuing over the length of some specified thing|
|3.||in accompaniment; together with some specified person or people: he says he'd like to come along|
|4.||forward: the horse trotted along at a steady pace|
|5.||to a more advanced state: he got the work moving along|
|6.||along with accompanying; together with: consider the advantages along with the disadvantages|
From the start, throughout, from end to end, as in I've known he was innocent all along. [c. 1600] Also see all along the line.