Band in Japan starts off ordering burgers in (3)
I believe the answer is:
obi
'band in japan' is the definition.
(type of Japanese belt)
'starts off ordering burgers in' is the wordplay.
'starts off' says to take the initial letters.
The initial letters of 'ordering burgers in' is 'OBI'.
(Other definitions for obi that I've seen before include "exotic waistband" , "Caribbean's charming" , "West Indian witchcraft" , "Japanese sash - African witchcraft" , "Sash worn on Japanese kimono" .)