from The American Heritage® Dictionary of the English Language, 4th Edition
- conj. During the time that; while: We will stay so long as you need us.
- conj. Inasmuch as; since: So long as you're driving into town, why not give me a ride?
- conj. Provided that: I will give you the book so long as you return it.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- Depending upon some condition or requirement; provided that; if, assuming; as long as.
Sorry, no etymologies found.