Wiktionary
a. 1 (context of a field or land English) Unturned with a plough, and thus retaining its original vegetation (usually grass). 2 (context figuratively English) Unexplored or unknown.
WordNet
Usage examples of "unploughed".
The Wanderer To see the clouds his spirit yearned toward so Over new mountains piled and unploughed waves, Back of old-storied spires and architraves To watch Arcturus rise or Fomalhaut, And roused by street-cries in strange tongues when day Flooded with gold some domed metropolis, Between new towers to waken and new bliss Spread on his pillow in a wondrous way: These were his joys.
But this new order of things--a ranch bounded only by the horizons, where, as far as one could see, to the north, to the east, to the south and to the west, was all one holding, a principality ruled with iron and steam, bullied into a yield of three hundred and fifty thousand bushels, where even when the land was resting, unploughed, unharrowed, and unsown, the wheat came up--troubled her, and even at times filled her with an undefinable terror.