uphill

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Located on high or higher ground.
• adjective Going up a hill or slope.
• adjective Marked by difficulty or strong resistance; laborious.
• adverb To or toward higher ground; up a slope.
• adverb Against adversity; with difficulty.
• noun An upward slope or incline.

from The Century Dictionary.

• Leading or going up a rising ground; sloping upward: as, an uphill road.
• Attended with labor, fatigue, or exertion; difficult; severe; fatiguing; burdensome: as, uphill work; hence, not having free course; hampered: as, an uphill acquaintance.
• noun Rising ground; ascent; upward slope.
• Upward; up, or as if up, an ascent: as, to walk uphill.

from the GNU version of the Collaborative International Dictionary of English.

• adjective Ascending; going up.
• adjective Attended with labor; difficult.
• adverb Upwards on, or as on, a hillside.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adverb up a slope, towards higher ground
• adverb by extension with difficulty
• adjective located up a slope or on a hill
• adjective going up a slope or a hill
• adjective by extension difficult or laborious
• noun An uphill route.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the upward slope of a hill
• adverb against difficulties
• adverb upward on a hill or incline
• adjective sloping upward