Dictionary.net

• An allowance, in addition to their pay, made to troops in India when in the field.

1914 - Nuttall's Standard dictionary of the English language
By Nuttall, P.Austin.

• An allowance to the officers serving in the East Indies in addition to their pay.

1874 - Etymological and pronouncing dictionary of the English language
By Stormonth, James, Phelp, P. H.