Step fathers (3)
I believe the answer is:
pas
This clue is a double definition.
'step' is the first definition.
(I know that pas is a type of step)
'fathers' is the second definition.
(pa is a kind of father)
(Other definitions for pas that I've seen before include "Dad's" , "Ballet duet" , "A bit of ballet" , "Office workers" , "Dancing step" .)