a·long 
(ə-lông, ə-lŏng)
(ə-lông, ə-lŏng)prep.
1. Over the length of: walked along the path.
2. On a line or course parallel and close to; continuously beside: rowed along the shore; the trees along the avenue.
3. In accordance with: The committee split along party lines over the issue.
adv.
1. Forward; onward: We drove along, admiring the view. Farther along, we passed a hitchhiker.
2. As company: Bring your friend along.
3. In accompaniment or association; together: packed an atlas along with other books. See Usage Note at together.
4. With one; at hand: Luckily, I had my camera along. Our guests should be along soon.
5. Informal Advanced to some degree: My father is getting along in years.
[Middle English, from Old English andlang, extending opposite : and-, facing; see ant- in the Appendix of Indo-European roots + lang, long; see LONG1.]