lump sum
US /ˈlʌmp sʌm/
UK /ˈlʌmp sʌm/

1.
somme forfaitaire, capital
a single payment made at one time, as opposed to a series of smaller payments made over time
:
•
She received a lump sum payment after selling her house.
Elle a reçu un paiement forfaitaire après avoir vendu sa maison.
•
He chose to take his pension as a lump sum rather than monthly payments.
Il a choisi de prendre sa pension en capital plutôt qu'en paiements mensuels.