An orphaned VM is a virtual machine that has been disconnected from its host. This problem happens in various network virtualization systems, indicating that a single virtual machine is not correctly connected to the greater software environment.
Techopedia explains Orphaned VM
The issue behind the "orphaned VM" is that virtual machines (VMs), or logical machines created by a virtualization system, are typically connected to a host that manages their implementation and use. There are various reasons why the system cannot find the host for an orphaned VM. These include deleted configurations, unsuccessful failover operations where backup strategies leave the machine disconnected, or even certain kinds of network stress, where the usual protocols become distorted in some way.
Systems administrators use different solutions for dealing with orphaned VMs under different kinds of network virtualization systems. In many cases, they can migrate an orphaned VM to another host. Alternatively, they can delete the orphaned VM and reappropriate the resources. This type of work is part of virtual network management and of the analysis and observation of how network virtualization works in the field.