1. (

• balloon

) large tough nonrigid bag filled with gas or heated air ;

2. (

• balloon ,

) small thin inflatable rubber bag with narrow neck ;

1. (

• balloon

) ride in a hot-air balloon; "He tried to balloon around the earth but storms forced him to land in China" ;

2. (

• balloon ,
• inflate ,
• billow

) become inflated; "The sails ballooned" ;