Meaning

noun an upholstered seat for more than one person

noun a room (as in a hotel or airport) with seating where people can wait

verb sit or recline comfortably

originOrigin uncertain. Perhaps borrowed from French s'allonger (“to lie down”). Compare French longer (“to walk along”). Compare also German lungern (“to hang or lounge around, linger”).

Etymology from Wiktionary, CC BY-SA 3.0