Land that is higher than the country around it and away from the coast — hills, high open ground, moorland. Not mountains exactly; uplands are gentler than that, but clearly higher and rougher than the flat farmland below. "Upland" is the word geographers, farmers, and nature writers reach for when they mean high country.

It works as a noun ("the upland of central Wales") but you meet it far more often as a description in front of another noun: upland farms, upland sheep, upland birds, an upland stream, upland soil. This is where the word earns its keep — upland farming is a real thing with its own difficulties (thin soil, cold, wind, short growing season), and calling a farm an upland farm tells another farmer a great deal in one word.

It is somewhat formal or technical. In ordinary conversation people say "up in the hills" or "the high country". You will meet upland in geography lessons, nature documentaries, government reports about farming, and hunting talk (in America, upland birds means pheasant, quail, grouse — the ones you hunt on high dry ground rather than in water).

The plural, uplands, is the more usual noun form for an actual region.