munch, nibble

cardiac sphincter

ravine, river, mountainside, creek, waterfall, cliff, mountain, canyon, crevasse, rivulet, riverbank, embankment, crag, snowfield, hillside, lake, cave, slopes, creek bed, riverbed, rapids, snowslide, glacier, horseshoe falls, escarpment, icefall, hill, hillock, valley, tributary, gulch, corrie, ledge, couloir, rockface, boulder, ridge, fjord, massif, tarns, kaieteur falls, seracs, precipices, cog railway, butte, hogback, ganges river, fourteener, cataract canyon, bernese alps, rafting, ropeway, harney peak, fiord, zambezi river, brahmaputra river, lassen peak, glade, dells, funicular railway, nanda devi, timberline, helvellyn, headwaters, gully, crater, meadow, footbridge, pond, brook, foothills, sugar loaf mountain, mount ranier, himalayas, crevice, flume, tsangpo, cableway, backcountry, billabong, plateaux, coire, treetops, scafell pike, esker, gondola, volcanic crater, rock outcrop, selkirk mountains, wasatch range, canyoneering, little bighorn river, himalayan, karakoram range, glen, trekking, tussocks, schuss, mountaintop, alp, trestle bridge, snowy mountains, gorges, canyons, defile, ravines, cirque, amphitheater, gulches, cavern, chasm, east, beveled, concave, northwest, recessed, sloped, southwest, bevelled, coast, convex, inclined, incurved, meatal, narrowest, puddle, south, steeper, undercut

cram, fill, fill up, flume, grand canyon, gulch, jam, olduvai gorge, stuff

arches national park, flume, grand canyon, gulch, mouth, olduvai gorge

alimentary canal, alimentary tract, digestive tract, digestive tube, gastrointestinal tract, gi tract

eat, mountain pass, notch, pass, passage, passageway, ravine

binge, defile, englut, engorge, esophagus, glut, gormandise, gormandize, gourmandize, gullet, ingurgitate, oesophagus, overeat, overgorge, overindulge, pig out, satiate, scarf out, stuff