Insufficient pressure; a marked drop in pressure(noun)
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Use "underpressure" in a sentence
"He's not aware of any single event that served as the immediate catalyst for Palin's decision, but adds that she was underpressure to make a decision whether or not she would seek another term as governor, so others in the state GOP could prepare for the race."
"He knew he was underpressure for answers now the Wave had lifted."
"What I needed to know was whether he'd been put underpressure, very great pressure to talk before they shot him, and whether to expect the same kind of thing if in fact they'd broken him and he'd blown my cover."