It’s not important, ballroom dance’s repeats both being foxtrot (5)
I believe the answer is:
chaff
But I can't explain it at all! Could you help me understand?
(Other definitions for chaff that I've seen before include "Light-hearted banter" , "Light banter - husks from corn" , "Corn-husks separated from the grain" , "Rubbish" , "shells" .)