Definition: The word "ospf3" refers to a version of OSPF that operates with three networks in addition to a single default network, known as the "stub router." It was introduced in OSPF 4.0 and is used for high-bandwidth networks such as Internet-of-Things (IoT) infrastructure or large-scale data centers. The word 'ospf3' signifies it's a newer version of the OSPF protocol, designed specifically for these scenarios.