1570s, "a game played with a large inflated leather ball," from It. pallone "large ball," from palla "ball," from Langobardic palla (from P.Gmc. *ball-, from PIE *bhel- (2) "to blow, swell;" see bole
) + -one, suffix indicating great size. Perhaps borrowed in part from Fr. ballon
(16c.), altered (after balle) from It. pallone. It also meant the ball itself (1590s), which was batted back and forth by means of large wooden paddles strapped to the forearms. In 17c., it also meant "a type of fireworks housed in a pasteboard ball" (1630s) and "round ball used as an architectural ornament" (1650s). Acquired modern meaning after Montgolfier brothers' flights, 1783. As a child's toy, it is attested from 1848; as "outline containing words in a comic engraving" it dates from 1844. The verb meaning "to swell, puff up" is attested from 1841. Trial balloon is congnate of French ballon d'essai.