1. requiring great exertion; laborious; difficult: an arduous undertaking.
2. requiring or using much energy and vigor; strenuous: making an arduous effort.
3. hard to climb; steep: an arduous path up the hill.
4. hard to endure; full of hardships; severe: an arduous winter.
"places can be arduous without things."
"wardens can be arduous for people."
"journeys can be arduous in extremes."
"tasks can be arduous."
"talks can be arduous."
This list can help you learn new vocabulary more quickly and be able explore other words more easily.