plaything, toy - an artifact designed to be played with

gasbag, envelope - the bag containing the gas in a balloon

hot-air balloon - balloon for travel through the air in a basket suspended below a large bag of heated air

lighter-than-air craft - aircraft supported by its own buoyancy

meteorological balloon - a small unmanned balloon set aloft to observe atmospheric conditions

ripcord - a cord that is pulled to open the gasbag of a balloon wide enough to release gas and so causes the balloon to descend

trial balloon - a balloon sent up to test air currents

aviate, pilot, fly - fly a plane

reflate - become inflated again

expand - become larger in size or volume or quantity; "his business expanded rapidly"