Patriarch’s name, old and historic at the start (4)
I believe the answer is:
noah
'patriarch's' is the definition.
(patriarch in the Bible)
'name old and historic at the start' is the wordplay.
'at the start' indicates taking the first letters.
The first letters of 'name old and historic' is 'NOAH'.
(Other definitions for noah that I've seen before include "He survived 40 days and 40 nights of rain" , "The first Arkwright!" , "Oh, an ark man" , "His sons were Shem, Ham and Japheth" , "Biblical patriarch" .)