1. A difficult or intricate assignment or piece of work that requires significant effort, skill, or planning to complete
Debugging the software was a complex task that took weeks to complete.
Corrigir os erros do software foi uma tarefa complexa que levou semanas para ser concluída.
2. An undertaking involving multiple interconnected elements or steps
Organizing the international conference proved to be a complex task.
Organizar a conferência internacional provou ser uma tarefa complexa.