heavy sledding (adjective) rugged: difficult, rigorous
Sinonime: aerial, alpine, altitudinous,
big,
colossal, elevated,
eminent,
flying,
formidable,
giant,
gigantic,
grand,
great, high rise, high-reaching, hovering,
huge,
immense,
large, lofty,
long, sky-high, sky-scraping, soaring,
steep, towering,
tremendous, uplifted, upraised
Antonime: dwarfed,
low, lowly,
short, stunted