If it distributes Linux, it's a distro. Thus ChromeOS, Android, Windows are all Linux distros.
If you have a different definition, best you can do with it is go brighten up some lawyer's day, I guess.
My understanding is that is has to have a certain level of the GNU core utilities in combination with the Kernel but yeah not really, it's hard to define, maybe the use of a package manager? Definitely nothing to do with GUI, probably a philosophy in mind, not sure at all to be honest.
a certain level of the GNU core utilities
Wouldn't that make Alpine, or OpenWRT, not a distro?
It is hard. We had Chimera Linux posted here yesterday, which has no GNU code at all. None of the early Linux distributions had package managers. The best I can tell, "pms" (package management system) written for Bogus Linux in 1993 was the earliest, but package management didn't hit the mainstream until at least 1995. Slackware didn't get a package manager until the mid-2000s. But we still all consider them distributions. (Right?)
Does Android really even use the Linux Kernel anymore? I thought they forked it about 15 years ago and at this point it has diverged so much its not even really the Linux kernel anymore.
No, it absolutely uses a Linux kernel.
From Wikipedia, the free encyclopedia
Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).
Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.
Community icon by Alpár-Etele Méder, licensed under CC BY 3.0