Butte

Etymology
From butte.

Noun

 * 1) 🇺🇸 an isolated hill with steep sides and a flat top

Thesaurus
anthill, barrow, brae, down, drumlin, dune, fell, foothills, hill, hillock, hummock, knob, knoll, molehill, monticle, monticule, moor, mound, sand dune, swell