A target is usually the name of a file that is generated by a program; examples of targets are executable or object files.

From ftp://ftp.gnu.org/old-gnu/Manuals/make-3.79.1/html_chapter/make_2.html

A phony target is one that is not really the name of a file; rather it is just a name for a recipe to be executed when you make an explicit request. 

From https://www.gnu.org/software/make/manual/html_node/Phony-Targets.html

So perhaps I should have used phony target.

Certainly people use and say target OS, but as there is only one real OS, that's a bit superfluous, a poetic construct so-to-speak.