adjective
1.
Synonyms: vigorous , dynamic, energetic, lusty, red-blooded, ||survigrous, vital
2.
Synonyms: hard 6, arduous, difficult, effortful, laborious, operose, toilful, toilsome, tough, uphill
Related Word: breathless, energy-consuming; mean, wicked; Herculean
Idioms: a long hard pull, an uphill climb, tough going
Contrasted words: comfortable, cushy, light, unburdensome
Antonyms: effortless