scour
UK[ˈskaʊə(r)]US[ˈskaʊər]
v
to clean or polish something by rubbing it hard with a rough material
v
to search a place or document thoroughly in order to find something
v
(of water or a current) to remove dirt or other matter from something by fast-flowing movement
Etymology
the verb 'scour' entered middle english from the old french 'escurer', meaning to clean or polish. this old french term likely has its roots in the late latin 'excurare', a compound of the latin intensive prefix 'ex-' and 'curare', meaning 'to take care of'. the semantic journey connects the core idea of 'taking thorough care' to the vigorous actions of cleaning by rubbing and, by extension, to the thoroughness implied in searching. the sense of erosion by water developed later, metaphorically extending the concept of a forceful, cleansing action to natural processes.
Analysis
the word is a simplex form derived from middle english, with its ultimate origin uncertain but likely related to old norse or latin influences.
Examples
she scoured the old pot until it shone.
detectives scoured the area for any clues.
the river had scoured a deep channel through the soft rock.