A couch is a piece of furniture designed for multiple people to sit on comfortably, usually found in living rooms, family rooms, or dens. Couches typically have cushioned seats, a back for leaning against, and arms on either side. They're also called sofas, though some people use “couch” for more casual furniture and “sofa” for fancier pieces.

Couches are where families gather to watch movies, where you curl up with a good book, or where friends sit together playing video games. Some couches fold out into beds for guests to sleep on. The phrase couch potato refers to someone who spends too much time lounging on the couch watching television instead of being active.

In psychology, people talk about “the therapist's couch” because patients traditionally lie on a couch during sessions. The word can also be used as a verb meaning to express something in a particular way: a principal might couch criticism in gentle language, or a diplomat might couch a warning in polite terms, choosing words carefully to soften the message while still getting the point across.