'Don't call me stupid.' said the Chenomeles
When pruning my Chaenomeles I remembered my RHS tutor telling me the name meant 'stupid bush' in Japanese. This is apparently because the branches grow in a tangled fashion and they don't like to be trained. Uncertain if this was just an English old wives tale, I checked it out with my good friend Jiro in Japan.
Sure enough Chaenomeles are called 'bo-keh (木瓜)' in Japanese like the word 'bokeh' which means stupid, mindless, or out of focus. The word stems from 'mokeh' (木/mok is tree, 瓜/ka is melon). The fruit are more apple than melon-like, but apples are a relatively new introduction to Japan. Thanks @bakase998 for verifying this.