English possesses dozens of nouns that mean “short sayings that encapsulate truth or wisdom passed on from previous generations.” Proverb and adage are two of them.
proverb: a short, traditional, and pithy saying; a concise sentence, typically metaphorical or alliterative in form, stating a general truth or piece of advice; an adage.
adage: a proverb or short statement expressing a general truth.
Efforts are made to draw a distinction between proverb and adage, but in common usage, the words are interchangeable. There may be a sense that adage is a classier word than proverb.
Because a saying becomes a proverb or an adage by being repeated from generation to generation, the expression “old adage” is often criticized for being redundant, but it is very common:
According to the famous old adage, all roads lead to Rome.
Remember the old adage, A picture’s worth a thousand words?
He said “President Reagan’s old adage about ‘trust but verify’ … is in need of an update
I confirmed with Brenda that what she is trying to convey to her students is the old writing adage “show, don’t tell.”
As that last quotation is from the Grammar Girl herself, Mignon Fogarty, I wouldn’t be too quick to criticize.
Numerous lists of proverbs and adages can be found on line, but their compilers don’t always distinguish between actual proverbs and quotations from song lyrics and literature. For example,
All you need is love (Beatle song, 1967)
‘Tis better to have loved and lost/Than never to have loved at all. (Tennyson, In Memoriam, 1850)
The female of the species is more deadly than the male. (Kipling, “The Female of the Species,” 1911.)
Many proverbs are couched as advice:
Don’t cross the bridge till you come to it.
Don’t put all your eggs in one basket.
Don’t rock the boat.
Let sleeping dogs lie.
Never let the sun go down on your anger.
Never tell tales out of school.
Waste not want not.
Judging by some of the questions that have stumped recent Jeopardy contestants, the passing on of proverbs seems to be in decline.