This article offers a detailed lexical semantic analysis of rude, the primary ethno-descriptor in the domain of “impoliteness” in Anglo society (Wierzbicka, 1997; cf. Fox, 2004), in the productive formula It's rude to VP, and in the fixed expression rude word. The semantic explications are framed in the simple Natural Semantic Metalanguage (NSM) universal primes. The reasoning is bolstered by Australian English data, gathered from Google searches.