Adage

An adage is a pithy saying that sums up a particular subject or situation.
The term "law" is sometimes applied to these, although they are usually less
rigorous ideas than legal laws or physical laws.

These may be interesting observations or relationships, practical or ethical
guidelines (also called rules of thumb), and even humorous parodies of
physical laws.

Adages often originate in popular fiction, or in Internet forums such as
Usenet. One literary personage renowned for his use of adages was Sancho
Panza in Miguel de Cervantes' novel Don Quixote. Through overuse, an adage
may become a clichˇ.