a flat coat of paint or varnish used by artists as a primer
"The artist applied a thin layer of couch to prepare the canvas before beginning the final portrait."
a narrow bed on which a patient lies during psychiatric or psychoanalytic treatment
"During her weekly psychoanalysis, she lay back on the couch while discussing her childhood memories."
An item of furniture, often upholstered, for the comfortable seating of more than one person.
"The farmer spent hours trying to dig out the dense mats of couch grass that had taken over his pasture."
Couch grass, a species of persistent grass, Elymus repens, usually considered a weed.
In plain English: A couch is a comfortable piece of furniture with cushions that you sit on, lie down on, or relax against.
"I fell asleep on the couch while watching television."
Usage: Use "couch" as the primary noun for any upholstered seat designed for multiple people. Avoid confusing it with "sofa," which typically implies back-to-back seating, though both terms are often used interchangeably in casual conversation.
To lie down; to recline (upon a couch or other place of repose).
"After a long day at work, he decided to couch on the sofa and watch television until he fell asleep."
In plain English: To couch something is to put it into comfortable or polite language so that people don't get upset by harsh truths.
"She decided to couch her criticism in polite terms so he wouldn't feel attacked."
A surname.
"The famous writer named Couch published his new novel last year."
The word couch entered English via Middle English and Old French as a doublet of "cwtch," originally deriving from a related verb meaning to lie down or recline. Its journey through these languages preserved its core sense while establishing the modern spelling we use today.