Proverbial (adjective)

1. Relating to or of the nature of a proverb; characteristic of a proverb; wise or pithy.
2. Used in reference to something that is well-known or frequently referred to, often as an example of a particular type of thing or behavior.

Origin:

From latin proverbium, from proverbus "famous, common".

Examples:

1. The phrase "a bird in the hand is worth two in the bush" is a proverbial expression of the value of what one has against the potential of what one may gain.
2. He was a master of the proverbial one-liner.
3. The proverbial cat has nine lives.
4. She is the proverbial black sheep of the family.
5. The proverbial grass is always greener on the other side.