What does "advance payment" mean?

The part of a contractually due sum that is paid or received in advance for a good, service or social security.

What is a synonym for "advance payment"?

Common synonyms include: partial payment, prepay, prepaying, prepayment, prepayments, retainers.

noun

noun ·Rare ·Advanced level

Noun

1
The part of a contractually due sum that is paid or received in advance for a good, service or social security.
"Near-synonym: down payment"