魯

adjective: stupid; dull, rude; crude
魯

The character carries several distinct senses under this same reading (surname, the ancient state of Lu, 'stupid/rude', bound morpheme in compounds like 魯肉飯) and it is unclear which is most salient as a standalone Teochew word, so the 'stupid; rude' adjective sense was picked as the most generally usable gloss.