exploding offer
n.— «With each week that passes since the original offer, the sum decreases as the candidate dithers (an “exploding offer’). But most students frown on such practices. “It’s a good way of paying off one’s debt in the college bar. But do companies really imagine we’d fall for such baits?’ one student said.» —“Spectrum: From milk round to gravy train” by Fiona Maddocks Times (London, England) July 8, 1986. (source: Double-Tongued Dictionary)