arduous

comparative more arduous · superlative most arduous

1. Needing or using up much energy; testing powers of endurance.

   The movement towards a peaceful settlement has been a long and arduous political struggle.

   2 more examples

   The slave-labour camps proliferated and became an important factor in the state economy, especially in regions where conditions were most arduous, as in the mines and forests of Siberia.

   1978 [1976], Leszek Kołakowski, translated by P[aul] S[teven] Falla, Main Currents of Marxism, volume III: The Breakdown, Oxford: Clarendon Press, translation of Główne nurty marksizmu: rozkład (in Polish), →ISBN, →OCLC, page 78

   Chelsea survived and can now turn their attentions to the Champions League final against Bayern Munich in Germany later this month as they face an increasingly arduous task to finish in the Premier League's top four.

   2012 May 5, Phil McNulty, “Chelsea 2-1 Liverpool”, in BBC Sport

2. obsoleteburning; ardent

   1805-1814, Dante, Henry Francis Cary (translator), The Divine Comedy Where flames the arduous Spirit of Isidore.

3. Difficult or exhausting to traverse.

   Beyond the river, an arduous slope rises 3286 feet in 13 miles.

   1974, Sue Bowder, The American biking atlas & touring guide, page 77

   2 more examples

   Mike looked up from the arduous mountain trail. They'd been climbing for five hours and he was beginning to feel irritable.

   1999, Scott Ciencin, Mike Fredericks, Dinoverse

   Survivor reaches as many as 28 million viewers who watch contestants win a new Pontiac or guzzle Mountain Dew after scaling an arduous cliff.

   2006, Jack W. Plunkett, Plunkett's Entertainment & Media Industry Almanac 2006