Synonyms:
- Herculean,
- abstruse,
- adverse,
- antagonistic,
- arduous,
- brutal,
- complex,
- conflicting,
- contrary,
- counter,
- counteractive,
- critical,
- delicate,
- demanding,
- detrimental,
- difficile,
- difficult,
- exacting,
- formidable,
- hairy,
- hard,
- hard-earned,
- hard-fought,
- harmful,
- hostile,
- in opposition,
- inimical,
- intricate,
- jawbreaking,
- knotted,
- knotty,
- laborious,
- mean,
- miserable,
- no picnic,
- operose,
- opposed,
- opposing,
- opposite,
- rigorous,
- rough,
- rugged,
- set with thorns,
- severe,
- sinister,
- spiny,
- steep,
- strenuous,
- stressful,
- thorny,
- ticklish,
- toilsome,
- tough,
- tricky,
- troublesome,
- troublous,
- trying,
- unfavorable,
- untoward,
- uphill,
- wicked,
- wretched