Why was clemency trending last week?
late 15c., in Scottish dreg-boat "boat for dredging," perhaps ultimately from root of drag (possibly via Middle Dutch dregghe "drag-net"). The verb is attested from c.1500 in Scottish. Related: Dredged; dredging.
To find or discover by effort and persistence: Let's dredge up more dirt on the candidate (1950s+)
(Job 24:6). See CORN.