March – ballroom dance (9)
I believe the answer is:
quickstep
This clue is a double definition.
'march' is the first definition.
(quickstep is a kind of march)
'ballroom dance' is the second definition.
(I know that quickstep is a type of ballroom dance)
(Other definitions for quickstep that I've seen before include "Lively dance" , "Modern ballroom dance" , "Fast foxtrot" , "dance music" , "Fast dance" .)