a room in a hotel, airport, theater, etc. where people can relax or wait
You could relax in the lounge while waiting for your flight.
a room with toilets that is in a public place, for example in a restaurant
Excuse me, I need to go to the restroom.
The apartment has four bedrooms and two bathrooms.
the part of a bar with more comfortable seating and more expensive drinks
They sat in a corner of the lounge bar until closing time.