Pronunciation: (hōld'bak"),[key] —n. 1. the iron or strap on the shaft of a horse-drawn vehicle to which the breeching of the harness is attached, enabling the horse to hold back or to back the vehicle.
2. a device for restraining or checking, as a doorstop or tieback.
3. a stop or delay: a holdback in negotiations. 4. a withholding: the holdback of a day's pay. 5. something, as a planned expenditure or allotment, that is withheld or deferred.