Definition from hubcap
“A social impact bond (also known as preventative social financing) is a type of outcome-based contract. Through a social impact bond, private investment is used to pay for interventions, which are delivered through service providers with a proven track record. The investors receive a financial return from government if and only if the intervention is successful.”
Going further
I've curated 400+ definitions just like this one in a tiny dictionary. In this glossary you can easily access, search and understand 400+ terms that service designers and other innovators use.