1
general::
1. Also, all along the line. All the way, throughout. For example, We've found numerous errors down the line. The first term dates from the mid-1900s, the variant from the second half of the 1800s. 2. Also, down the road. At a future point or end. For example, Somewhere down the road I think he'll be elected to high office. [Second half of 1900s]
American Heritage Idioms