1. a person who talks or writes foolishly or at tedious length; someone who speaks nonsense
Usage: informal; chiefly British
2. a person who drools or slobbers
Usage: informal

Examples

• He dismissed the critic as a driveller who understood nothing about modern art.
• The old driveller rambled on for hours without making a single coherent point.
• Don't listen to that driveller; his opinions are worthless.
• She had no patience for the driveller at the party who wouldn't stop talking nonsense.
• The politician was branded a driveller by the opposition for his incoherent speech.