slacken
US /ˈslæk.ən/
UK /ˈslæk.ən/

1.
afrouxar, diminuir, relaxar
make or become less active or intense
:
•
The rain began to slacken.
A chuva começou a diminuir.
•
He needs to slacken his pace if he wants to finish the marathon.
Ele precisa diminuir o ritmo se quiser terminar a maratona.