Is prefixing “old” before the word “adage” correct or not?

Question

Is it correct to say "old adage" or simply the word "adage" itself is enough because most of the adages are old

Answer 1

An adage is essentially a proverb; a well-known expression regarded to be general truth.

Of course you need not put the word "old" in front of "adage" – adage can stand on its own.

This Ngram shows that the phrase "old adage" is relatively common; about half the time "adage" is used, it appears to be prefixed by "old."

But commonality doesn't imply correctness, especially in this case. "Old adage" may be overused, to the point where it reads trite. (When writing, remember the adage, avoid trite expressions).

Here are three literary quotes with the word adage (the first omits the old; the second leaves it in, and the third sheds light on the answer to your question):

The adage "beauty is in the eye of the beholder" suggests that attractiveness varies across individuals and cultures. (Rhodes & Zebrowitz, Facial attractiveness: evolutionary, cognitive, and social perspectives)

The old adage "beauty is only skin deep" applies to upholstered furniture. (L. Elliott, from Old House Interiors magazine, Spring 1996)

It is sometimes claimed that the expression old adage is redundant, inasmuch as a saying must have a certain tradition behind it to count as an adage in the first place. But the word adage is first recorded in the phrase old adage, showing that this redundancy itself is very old. (The American Heritage Book of English Usage)