Wiktionary
n. (context aviation astronautics English) A sealed, full-body garment, usually with an attachable helmet, which maintains air pressure or mechanical pressure around the body of an astronaut or aviator to compensate for the low density of the air at high altitudes.
WordNet
n. protective garment consisting of an inflatable suit for space or high altitude flying
Wikipedia
A pressure suit is a protective suit worn by high-altitude pilots who may fly at altitudes where the air pressure is too low for an unprotected person to survive, even breathing pure oxygen at positive pressure. Such suits may be either full-pressure (i.e. a space suit) or partial-pressure (as used by aircrew). Partial-pressure suits work by providing mechanical counter-pressure to assist breathing at altitude.
Usage examples of "pressure suit".
To avail yourself of this privilege you should return the pressure suit via express collect to Goodyear Corporation (Special Appliances Division, attn: Salvage), Akron, Ohio, on or before the 15th of September.
But the crossbow is all I have, and it will penetrate- make holes in a Navy pressure suit.
Inside the pressure suit it took some effort just to move his legs forward, and by the time he got to the bird he could feel his lungs dragging at the oxygen fed to him by the suit.
It took him a full hour to be loaded into his pressure suit, for instance.
His own pressure suit sat propped up in a corner like a headless stocking-doll where he had left it, but Aziz's suit was gone.