Real Time Gross Settlement - RTGS
The continuous settlement of payments on an individual order basis without netting debits with credits across the books of a central bank.
Investopedia Commentary
Basically, this is a system for large-value interbank funds transfers. This system lessens settlement risk because interbank settlement happens throughout the day, rather than just at the end of the day.
See also: Capital Gain Tax, Commission
Also spelled: RTGS