1. to begin functioning or working; to commence business or activity
The factory will start operation next month.
A fábrica iniciará operação no próximo mês.
2. to put into effect or execution; to commence a planned activity
We are ready to start operation on the new project.
Estamos prontos para iniciar a operação do novo projeto.
3. to begin a military, tactical, or strategic action
The troops will start operation at dawn.
As tropas iniciarão a operação ao amanhecer.