o·ver·pres·sure 
(ō′vər-prĕshər)
(ō′vər-prĕshər)n.
1. A transient air pressure, such as the shock wave from an explosion, that is greater than the surrounding atmospheric pressure.
2. Geology Pore or subsurface pressure that exceeds normal hydrostatic pressure at a given depth.
tr.v. o·ver·pres·sured, o·ver·pres·sur·ing, o·ver·pres·sures
To cause or subject to overpressure.
o′ver·pres′sur·i·zation (-ĭ-zāshən) n.