arduo
arduous, grueling
adjective AHR-dwoh Rare
Origin: Latin arduus (steep, difficult)
Usage Note
Arduo describes tasks requiring great effort — physical, intellectual, or logistical. It is a formal, written-register adjective; everyday speech more often uses difícil or duro. Commonly paired with tarea ardua (arduous task) or trabajo arduo (grueling work).
Examples
"Fue un camino arduo hasta la cima."
Natural Translation
It was an arduous path to the summit.

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