Poshness, meaning elegance, luxury and sophistication, has a number of antonyms that can be used to describe something or someone that is the complete opposite. For instance, unrefined, untidy, dowdy, scruffy and sloppy are words that denote a lack of poshness. Others like unimpressive, unglamorous, plain, basic, and shabby express a certain level of dullness and mediocrity. If one is looking for alternatives in terms of style, they can choose from the likes of casual, informal, simple and relaxed - words that often reflect a more laid-back, rustic kind of vibe. Whatever the context, opposites always have a way of painting a vivid picture of what we want to express.