from
The Collaborative International Dictionary of English v.0.48
pressurize \pressurize\ v. t.
To increase the pressure on (a gas or liquid); as,
pressurized oxygen.
Syn: supercharge, apply pressure to.
[WordNet 1.5]
2. To increase and maintain a pressure in (a compartment or
container), above that of the ambient pressure; -- of
airplanes, space suits, and diving bells, for example; as,
the airplane cabin was pressurized for the comfort of the
passengers; the sterile room was pressurized to prevent
contamination.
[WordNet 1.5 + PJC]
{negatively pressurized} maintained at a pressure somewhat
below that of ambient pressure; -- a technique sometimes
used to keep airborn materials in a room from escaping
out; as, the biohazard lab was negatively pressurized to
keep hazardous biological agents from escaping into the
environment.
[PJC]