From WordNet (r) 2.0 (August 2003) [wn]:
ballooning
n : flying in a balloon
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Ballooning \Bal*loon"ing\, n.
1. The art or practice of managing balloons or voyaging in
them; the sport of riding in balloons.
Syn: balloonry (archaic)
[1913 Webster +PJC]
2. (Stock Exchange) The process of temporarily raising the
value of a stock, as by fictitious sales. [U.S.]
[1913 Webster]