Sayings of modern times (6)
I believe the answer is:
'sayings' is the definition.
(adage is a kind of saying)
'modern times' is the wordplay.
'modern' becomes 'ad' (I've seen this in other clues).
'times' becomes 'ages' (age is a kind of time).
'of' is the link.
(Other definitions for adages that I've seen before include "Proverbs from sad age" , "Proverbs or maxims" , "Wise old sayings" , "'Proverbs, true sayings (6)'" , "Much-used wise sayings" .)