UN*X or *nix
Unix-like do not share source code with UNIX unlike UNIX variants
UNIX-like Distributions
UNIX Variants
UNIX Distribution Notion

Unix-like
A Unix-like operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Unix-like application is one that behaves like the corresponding Unix command or shell. Although there are general philosophies for Unix design, there is no technical standard defining the term, and opinions can differ about the degree to which a particular operating system or application is Unix-like.
https://en.wikipedia.org/wiki/Unix-like

Seonglae Cho