Number of Worthies (4)
I believe the answer is:
nine
'number of worthies' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for nine that I've seen before include "A stitch in time saves them" , "and 23: Flash in the pan" , "Number of Muses and days in a Novena" , "SECOND PART OF 14" , "One more than fourteen across" .)