couch potato(n = noun.person) - an idler who spends much time on a couch (usually watching television);
is a kind of bum, do-nothing, idler, layabout, loafer

N  incogitancy, vacancy, inunderstanding, fatuity thoughtlessness, vacuity, couch potato, vegetable, vacant, unintellectual, unideal, unoccupied, unthinking, inconsiderate, thoughtless, mindless, no-brain, vacuous, absent, diverted, irrational narrow-minded, unthought of, undreamt 'of, unconsidered, off one's mind, incogitable, not to be thought of, absence d'esprit, pabulum pictura pascit inani.

air potato, baked potato, brazilian potato tree, colorado potato beetle, couch, couch grass, covered couch, giant potato creeper, hot potato, indian potato, irish potato, jacket potato, little potato, mashed potato, potato, potato bean, potato beetle, potato blight, potato bug, potato chip, potato disease, potato family, potato fern, potato fungus, potato mildew, potato mold, potato mosaic, potato moth, potato murrain, potato nose, potato pancake, potato peel, potato peelings, potato race, potato salad, potato scab bacteria, potato skin, potato tree, potato tuber moth, potato tuberworm, potato vine, potato wart, potato wart fungus, potato worm, potato yellow dwarf, potato yellow-dwarf virus, studio couch, sweet potato, sweet potato vine, telingo potato, uruguay potato, uruguay potato vine, white potato, white potato vine, wild potato, wild potato vine, wild sweet potato vine, yellow dwarf of potato