"DNA Alias name entered as part of the Logical Web Application name for the Load Balancing address was added to the Foundation Services server host file. LCM was then able to determine that the LWA given name was actually resolvable to be the Foundation Services node name."
So you can see that LWA stands for Logical Web Application.
logical Web application An aliased reference used to identify the internal host name, port, and context of a Web application. In a clustered or high-availability environment, this is the alias name that establishes a single internal reference for the distributed components. In EPM System, a nonclustered logical Web application defaults to the physical host running the Web application.