Not really a cloud developer, so I looked up a couple of links and I haven't been able to find any uses of the term other than referring to a single-tenant machine that you have complete control over, as opposed to virtualized solutions.

https://en.wikipedia.org/wiki/Bare-metal_server https://www.ibm.com/cloud/bare-metal-servers/hosting-solutio... https://www.ionos.com/digitalguide/server/know-how/bare-meta... https://www.rackspace.com/library/what-is-a-bare-metal-serve...