the.com/fainting couch

means A low, one-armed upholstered sofa, angled for reclining, originally meant for resting (or theatrically swooning) in restrictive dress.

from The couch itself dates to 18th–19th century furniture design, often linked to the recamier-style chaise longue; the 'fainting' part is folk history layered on top — tight corsets really could restrict breathing enough to cause lightheadedness, and Victorian parlors kept chaises handy, but 'fainting couch' as a name is more a later, wry retronym than a period term furniture makers actually used.