scour1 / skou(ə)r/ • v. [tr.] clean or brighten the surface of (something) by rubbing it hard, typically with an abrasive or detergent: he scoured the bathtub. ∎ remove (dirt or unwanted matter) by rubbing in such a way: use an electric toothbrush to scour off plaque. ∎ (of water or a watercourse) make (a channel or pool) by flowing forcefully over something and removing soil or rock: a stream came crashing through a narrow cavern to scour out a round pool below.• n. 1. the action of scouring or the state of being scoured, esp. by swift-flowing water. ∎ [in sing.] an act of rubbing something hard to clean or brighten it: give the floor a good scour.2. (also scours) diarrhea in livestock, esp. cattle and pigs.DERIVATIVES: scour·er n.scour2 • v. [tr.] subject (a place, text, etc.) to a thorough search in order to locate something: David scoured each newspaper for an article on the murder.