Expensive, stylish, and clearly meant to be noticed — a swanky hotel, a swanky restaurant, a swanky new car. It is an informal, spoken word, and the feeling behind it matters more than the price. When you call a place swanky you are saying it is grand, but you are also standing slightly outside it, half admiring and half amused: this place is showing off, and you can see it showing off. So 'a swanky bar' suggests marble and gold taps and prices you have to look at twice. Said about a person or the way they act, it means showy, pleased with oneself — 'don't get swanky' means don't put on airs. That older use is now much rarer than the 'expensive and stylish' one, but it explains the flavour the word still has. It feels a little old-fashioned and light-hearted; younger speakers say 'fancy' or 'posh' more often, and 'swanky' often turns up when someone is gently teasing — 'ooh, swanky' when a friend shows off a new phone. It is not really rude, but it is never quite pure praise. Use 'swankier' and 'swankiest'.