1. well-known because mentioned in a proverb
2. widely known and spoken of; famous or notorious

Examples

• He was caught with his hand in the proverbial cookie jar.
• The proverbial early bird catches the worm.
• She’s always the proverbial life of the party.
• They were looking for a needle in the proverbial haystack.
• His proverbial bad luck struck again.
• The company’s proverbial deep pockets helped them survive the crisis.
• It was the proverbial calm before the storm.