Bolder, having aged (3)
I believe the answer is:
old
'aged' is the definition.
(similar in meaning)
'bolder having' is the wordplay.
'having' says the answer is hidden in the clue.
'OLD' is hidden within 'bolder'.
(Other definitions for old that I've seen before include "Former, previous" , "No longer young" , "Stale" , "out of the ark" , "Venerable" .)