1. to gradually decrease in speed, energy, or progress toward the conclusion of something
The team started strong but lost momentum at the end of the game.
O time começou bem, mas perdeu o ritmo no final do jogo.
2. to fail to maintain enthusiasm or effectiveness as something approaches completion
The writer's novel lost momentum at the end, making the conclusion feel rushed.
O romance do escritor perdeu o ritmo no final, fazendo a conclusão parecer apressada.