Start off bit before a dance (5)
I believe the answer is:
rumba
'dance' is the definition.
(rumba is a kind of dance)
'start off bit before a' is the wordplay.
'start off' means to remove the first letter (I've seen 'starting off' mean this (the starting letter is removed)).
'bit' becomes 'crumb' (crumb is a kind of bit).
'before' is a charade indicator (letters next to each other).
'crumb' with its initial letter taken away is 'rumb'.
'rumb'+'a'='RUMBA'
(Other definitions for rumba that I've seen before include "One from Cuba" , "number of steps" , "Style of dance" , "Dance originating in Cuba" , "Strictly round" .)