Synonyms and related words :
Herculean, abruptness, abstruse, acclinate, acclivitous, acclivity, anabasis, anabatic, arduous, ascendant, ascending, ascension, ascensional, ascensive, ascent, aslant, aslantwise, aslope, at a slant, atilt, backbreaking, brutal, burdensome, clamber, climb, climbing, complex, critical, crushing, delicate, demanding, difficile, difficult, downgrade, downhill, effortful, elevation, escalade, exacting, forced, formidable, fountain, grueling, gush, gyring up, hairy, hard, hard-earned, hard-fought, heavenward, heavy, hefty, in the ascendant, increase, intricate, jawbreaking, jet, jump, killing, knotted, knotty, labored, laborious, leap, leaping, levitation, mean, mount, mounting, no picnic, not easy, off plumb, onerous, operose, oppressive, painful, precipitousness, punishing, rakingly, rampant, rearing, rigorous, rise, rising, rising ground, rocketing up, rough, rugged, saltation, saltatory, scandent, scansorial, set with thorns, severe, shooting up, skyrocketing, skyward, slantingly, slantways, slantwise, slaunchways, slopeways, slopingly, soaring, spiny, spiraling, spout, spring, springing, spurt, steep, steepness, strained, strenuous, surge, takeoff, taking off, thorny, ticklish, tipsily, toilsome, tough, tricky, troublesome, up, up attic, up north, up steps, upalong, uparching, upclimb, upcoming, updraft, upgang, upgo, upgoing, upgrade, upgrowth, uphillward, upleap, uplift, uplong, upping, uprisal, uprise, uprising, uprush, upshoot, upslope, upsloping, upstairs, upstream, upstreamward, upsurge, upsurgence, upsweep, upswing, uptown, upward, upwards, upwith, vault, verticalness, wearisome, wicked, zooming