1. A beginning or commencement that proceeds without problems, delays, or complications
The project had a smooth start with all team members on board from day one.
O projeto teve um início tranquilo com todos os membros da equipe desde o primeiro dia.
2. In motorsports or racing, an engine or vehicle starting without stuttering or mechanical issues
The car engine gave a smooth start despite the cold weather.
O motor do carro teve um funcionamento suave apesar do frio.