I'll be obtuse, and claim it means "JavaScript-like". You know, multiple "truthy" values, the inability to detect the difference between arrays and objects, a weird mashup of OO and functional abilities, `=== undefined` but `isNaN()`, and no real difference between integers and floats, and all the math weirdness that goes with them. Browsers implementing the same thing different ways, interacting with a system (the DOM) that's the same but different everywhere, and patched together by multiple, usually-mutually-exclusive libraries that everyone uses instead of the actual language.
(disclaimer: I've come to quite like JS, it's made some of my experiments phenomenally simple. but it's weird.)