From WordNet (r) 3.0 (2006) [wn]:
uphill
adv 1: against difficulties; "she was talking uphill"
2: upward on a hill or incline; "this street lay uphill"
adj 1: sloping upward [syn: acclivitous, rising, uphill]
n 1: the upward slope of a hill
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Uphill \Up*hill"\, adv.
Upwards on, or as on, a hillside; as, to walk uphill.
[1913 Webster]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Uphill \Up"hill`\, a.
1. Ascending; going up; as, an uphill road.
[1913 Webster]
2. Attended with labor; difficult; as, uphill work.
[1913 Webster]