gambol

Merriam-Webster's Word of the Day for January 31, 2012 is:

gambol • \GAM-bul\  • verb
: to skip about in play : frisk, frolic

Examples:
The children scamper and gambol about the playground with seemingly endless energy.

"Strong binoculars … allow patrons to spy on the sea otters, pelicans, cormorants and other creatures that gambol among the bay kelp." -- From an article by Peter Magnani in the San Jose Mercury News, October 10, 2011

Did you know?
In Middle French, the noun "gambade" referred to the frisky spring of a jumping horse. In the early 1500s, the English word "gambol" romped into print as both a verb and a noun. (The noun means "a skipping or leaping about in play.") The English word is not restricted to horses, but rather can be used of any frolicsome creature. It is a word that suggests levity and spontaneity, and it tends to be used especially of the lively activity of children or animals engaged in active play.