| Main Entry: | |
| Part of Speech: | adjective |
| Definition: | going up |
| Synonyms: | acclivous, ascending, climbing, mounting, rising, skyward, sloping upward, toward summit, up, uprising |
| Antonyms: | downhill |
| Main Entry: | arduous |
| Part of Speech: | adjective |
| Definition: | difficult, hard to endure |
| Synonyms: | backbreaking, burdensome, exhausting, fatiguing, formidable, grueling, harsh, heavy, labored, laborious, murder, no picnic, onerous, painful, punishing, rigorous, rough, severe, strenuous, taxing, tiring, toilsome, tough, troublesome, trying, uphill |
| Antonyms: | easy, facile, motivating |
| Main Entry: | difficult |
| Part of Speech: | adjective |
| Definition: | hard on someone; hard to do |
| Synonyms: | Gargantuan, Herculean, ambitious, arduous, backbreaker, bothersome, burdensome, challenging, crucial, demanding, difficile, easier said than done, effortful, exacting, formidable, galling, hard-won, heavy, immense, intricate, irritating, labored, laborious, no picnic, not easy, onerous, operose, painful, problem, problematic, prohibitive, rigid, severe, stiff, strenuous, titanic, toilsome, tough, troublesome, trying, unyielding, uphill, upstream, wearisome |
| Antonyms: | calm, easy, free, manageable, plain, simple, uncomplicated |
| Main Entry: | formidable |
| Part of Speech: | adjective |
| Definition: | difficult, overwhelming |
| Synonyms: | all-powerful, arduous, awesome, ballbuster, challenging, colossal, dismaying, effortful, great, hard, impressive, indomitable, intimidating, labored, laborious, mammoth, mighty, murder*, onerous, overpowering, powerful, puissant, rough go, rough*, staggering, strenuous, tall order, toilsome, tough proposition, tough*, tremendous, uphill |
| Antonyms: | easy, not hard, pleasant, trivial |
| Main Entry: | hard |
| Part of Speech: | adjective |
| Definition: | difficult, exhausting |
| Synonyms: | Herculean, arduous, backbreaking, bothersome, burdensome, complicated, demanding, difficile, distressing, effortful, exacting, fatiguing, formidable, grinding, hairy*, heavy*, intricate, involved, irksome, knotty, labored, laborious, mean, merciless, murder, onerous, operose, rigorous, rough, rugged, scabrous, serious, severe, slavish, sticky, strenuous, terrible, tiring, toilful, toilsome, tough, troublesome, unsparing, uphill battle, uphill, wearing, wearisome, wearying |
| Antonyms: | easy, facile, mild, simple |
| Main Entry: | knotty |
| Part of Speech: | adjective |
| Definition: | troublesome |
| Synonyms: | Gordian, baffling, complex, complicated, difficult, effortful, elaborate, formidable, hard, intricate, involved, labyrinthine, mazy, mystifying, nodulous, perplexing, problematical, puzzling, ramified, reticular, rough, rugged, sophisticated, sticky*, terrible, thorny, tough, tricky, uphill |
| Antonyms: | simple, uncomplicated, untroublesome |
| Main Entry: | labored |
| Part of Speech: | adjective |
| Definition: | difficult to understand, unclear |
| Synonyms: | affected, arduous, awkward, clumsy, contrived, effortful, forced, hard, heavy, inept, maladroit, operose, overdone, overwrought, ponderous, stiff, strained, strenuous, studied, toilsome, unnatural, uphill, weighty |
| Antonyms: | easy, facile, natural, relaxed |
| Main Entry: | rugged |
| Part of Speech: | adjective |
| Definition: | difficult, rigorous |
| Synonyms: | arduous, demanding, exacting, formidable, hairy*, hard, harsh, heavy sledding, heavy*, knotty, laborious, large order, mean, murder*, no picnic, operose, rough, stern, strenuous, taxing, tough, trying, uncompromising, uphill |
| Antonyms: | easy, facile |
| Main Entry: | stiff |
| Part of Speech: | adjective |
| Definition: | difficult |
| Synonyms: | arduous, exacting, fatiguing, formidable, hard, laborious, tough, trying, uphill |
| Antonyms: | easy |