slacken
US /ˈslæk.ən/
UK /ˈslæk.ən/

1.
rallentare, allentare, diminuire
make or become less active or intense
:
•
The rain began to slacken.
La pioggia iniziò a diminuire.
•
He needs to slacken his pace if he wants to finish the marathon.
Deve rallentare il suo passo se vuole finire la maratona.