Isomorphic JavaScript
A JavaScript application which can be executed in both a browser and a non-browser runtime. This was the first term used to describe this concept, but "Universal JavaScript" now has wider acceptance. Mathematicians and functional programmers will scoff at you if you use "isomorphic" to describe JavaScript, so save face by using "universal" instead.
You aren't writing isomorphic JavaScript? Ha, you remind me of my old Java coworkers.