Fiddle is and anciently ubiquitous word with many derivations as can be proven, but to call an Erhu a Chinese Fiddle is to miss the point rather, though ethnomusicolists would no doubt call it a category of spike-fiddle, this is by way of taxonomy rather than naming per-se.

But then again, I've seen the Sanxian described as a Chinese Banjo, and, more absurdly, the Sheng as a Chinese Mouthorgan.