Dads' sisters (5)
I believe the answer is:
aunts
'dad's sisters' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for aunts that I've seen before include "Parents' sisters" , "Elderly female relations" , "Relatives get an odd US tan" , "Sally and others" , "Relatives get a peculiar US tan" .)