from The American Heritage® Dictionary of the English Language, 4th Edition
- adv. Toward or near the source of a river; in the direction opposite to that of the current: rowing upriver; upriver rapids.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adv. towards the source of a river
- adv. against the current
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adv. toward the source or against the current
up- + river (Wiktionary)