Merriam-Webster's Collegiate® Dictionary, 11th Edition
BALLOON
I. noun see: ball
Date: 1783
a nonporous bag of light material that can be inflated especially with air or gas: 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 (as a gondola with passengers), an inflatable bag (as of rubber or plastic) usually used as a toy or for decoration, the outline enclosing words spoken or thought by a figure especially in a cartoon,
II. adjective
Date: circa 1786
relating to, resembling, or suggesting a balloon , being or having a final installment that is much larger than preceding ones in a term or installment note,
III. verb
Date: 1841
intransitive verb to swell or puff out ; expand , to ascend or travel in or as if in a balloon, to increase rapidly , transitive verb inflate , increase