1 to go along

2 to follow

1 along the sides of the road

2 by the wayside

1 front-line

2 forward position

3 outpost

4 extending ahead

5 frontier (of science, technology etc)

1 along

2 to follow (a line, tradition etc)

3 to carry on

4 to trim (a border with braid, tape etc)

5 border

6 edge

1 coastal area

2 littoral or riparian