Brown to leave dance (5)
I believe the answer is:
tango
'dance' is the definition.
(I know that tango is a more specific form of the action dance)
'brown to leave' is the wordplay.
'brown' becomes 'tan' (tan is a kind of brown).
'to leave' becomes 'go' (both can mean to depart).
'tan'+'go'='TANGO'
(Other definitions for tango that I've seen before include "uniform to follow" , "Dance originating in Argentina" , "tee" , "Dance music" , "Last - in Paris (film)" .)