Answer: underrun

AnswerCrossword Clue
UNDERRUNSpending less than budget, say
UNDERRUNPass beneath.
underruninstance of costing or spending less than estimated
underrunto run, pass, or go under
underrunto pass beneath (a stretched rope, net, etc.) in a boat or the like for the purpose of inspection or repairs
underrunto pass or extend under
underrunsomething that runs or passes underneath, as a current
underrunproduction run of a manufactured or printed item below the quantity ordered