scour 1 
(skour)
(skour)v. scoured, scour·ing, scours
v.tr.
1.
a. To clean, polish, or wash by scrubbing vigorously: scour a dirty oven.
b. To remove by scrubbing: scour grease from a pan.
2. To remove dirt or grease from (cloth or fibers) by means of a detergent.
3. To clean (wheat) before the milling process.
4. To clear (an area) by freeing of weeds or other vegetation.
5. To clear (a channel or pipe) by flushing.
v.intr.
1. To scrub something in order to clean or polish it.
2. To have diarrhea. Used of livestock.
n.
1. A scouring action or effect.
2. A place that has been scoured, as by flushing with water.
3. A cleansing agent for wool.
4. scours (used with a sing. or pl. verb) Diarrhea in livestock.
[Middle English scouren, from Middle Dutch scūren, from Old French escurer, from Late Latin excūrāre, to clean out : Latin ex-, ex-, Late Latin cūrāre, to clean (from Latin, to take care of, from cūra, care; see CURE).]
scourer n.