vacuum

‘vekcu-am 1. empty space; an enclosed space from which the air or other gas has been removed, by means of a pump or otherwise. forced vacuum, a partial vacuum, or decrease of pre ure or density which 1s forced upon the air or other fluxd adjacent to an aerofezl or other surface which is acting upon it. compare forced pre ure, under pre ure. valve vetv 1. [also spelt valv] a device or appliance designed to contgol the flow of a fluid, as gas or air, thru a pipe, outlet, or mlet, as the one inserted at the top of a balloon, for letting out inflating-gas. emergency valve, a balloonzvaly which works automatically an case of an emergency.