scour

Concise Oxford English Dictionary © 2008 Oxford University Press:
scour1

▶verb

• 1 clean or brighten by vigorous rubbing, typically with an abrasive or detergent.

  ■ remove (dirt or unwanted matter) by rubbing in such a way.

• 2 (of running water) erode (a channel or pool).

• 3 (of livestock) suffer from diarrhoea.

▶noun

• 1 the action of scouring or the state of being scoured.

• 2 (also scours) diarrhoea in livestock, especially cattle and pigs.

– derivatives
scourer noun.

– origin ME: from MDu., Mid. Low Ger. schūren, from OFr. escurer, from late L. excurare ‘clean (off)’.

Concise Oxford English Dictionary © 2008 Oxford University Press:
scour2

▶verb

• 1 subject to a thorough search.

• 2 move rapidly.

– origin ME: rel. to obs. scour ‘moving hastily’, of unknown origin.