1) Alter 2) Change 3) Maintain a certain pressure 4) Modify 5) Pressurise 6) Supercharge 7) To pressure-cook 8) To put pressure on 9) To put under pressure 1) Force 2) Intimidate 3) Pressurise 4) Push 
[v] - maintain a certain pressure 2. [v] - increase the pressure, as of airplane cabins
to raise the internal atmospheric pressure of to the required or desired level: to pressurize an astronaut's spacesuit before a walk in space. · to maintain normal air pressure in (the cockpit or cabin of an airplane) at high altitudes. · to apply pressure to (a gas or liquid); supercharge. · to pressure-cook.