balloon Definition

a nonporous bag of light material that can be inflated especially with air or gas: such as

a bag that is filled with heated air or a gas lighter than air so as to rise and float in the atmosphere and that usually carries a suspended load (such as a gondola with passengers)

an inflatable bag (as of rubber or plastic) usually used as a toy or for decoration

relating to, resembling, or suggesting a balloon

having or being a final installment that is much larger than preceding ones in a term or installment note

to swell or puff out : expand

to ascend or travel in or as if in a balloon

to increase rapidly

dilation of an obstructed atherosclerotic artery by the passage of a balloon catheter through the vessel to the area of disease where inflation of the catheter's tip compresses the plaque against the vessel wall

a catheter with an inflatable tip which can be expanded (as by air or water) especially to hold the catheter in place or to expand a partly closed or obstructed bodily passage, opening, or vessel (such as a coronary artery) —called also balloon-tipped catheter

a perennial Asian herb (Platycodon grandiflorus) cultivated for its star-shaped flowers which open from buds resembling balloons

a flexible low-pressure pneumatic tire with a large cross section designed to provide cushioning

a tropical American vine (Cardiospermum halicacabum) of the soapberry family bearing large ornamental pods

a final payment that is much larger than any earlier payment made on a debt

a small captive balloon used to support wires or nets as protection against air attacks