Definition:
Savvy means someone who is shrewd and perspective, business savvy is an individual expert at business. He shows keenness and quickness in understanding and dealing with a “business situation” in a manner that is likely to lead to a good outcome
It is essential that the Product Owner (PO) to understand the business. PO is a decision maker regarding what is in or out of product, having deep understanding of the business, market conditions, customer and users. This type of understanding is developed over years of working in the domain. To be a successful product owner, he should be business-savvy.
Further Reading:
BOOK: SUCCEEDING WITH AGILE Software Development Using Scrum by Mike Cohn