1. A challenging, difficult, or strenuous task, project, or venture that requires significant effort and persistence to accomplish
Building a successful startup from scratch is an arduous enterprise that requires dedication and resilience.
Construir uma startup bem-sucedida do zero é uma empresa árdua que exige dedicação e resiliência.
2. An ambitious undertaking characterized by substantial obstacles and hardships
The restoration of the historic monument proved to be an arduous enterprise.
A restauração do monumento histórico mostrou-se uma empresa árdua.