Source : Webster's Revised Unabridged Dictionary (1913)

Uphill \Up*hill"\, adv.
   Upwards on, or as on, a hillside; as, to walk uphill.

Uphill \Up"hill`\, a.
   1. Ascending; going up; as, an uphill road.

   2. Attended with labor; difficult; as, uphill work.

Source : WordNet®

uphill
     adj 1: sloping upward [syn: {acclivitous}, {rising}]
     2: hard to overcome or surmount; "a stiff hike"; "a stiff
        exam"; "an uphill battle against a popular incumbant"
        [syn: {stiff}]
     n : the upward slope of a hill
     adv 1: against difficulties; "she was talking uphill"
     2: upward on a hill or incline; "this street lay uphill"