Relative; silent (3)
I believe the answer is:
mum
I believe this is a double definition.
'relative' is the first definition.
(I know that mum is a type of progenitor)
'silent' is the second definition.
(keep mum)
(Other definitions for mum that I've seen before include "Parent - shtoom" , "old lady" , "member of the family" , "Quiet; relative" , "Keep quiet, mother" .)