Here are some definitions I found:
From InvestorWords: A large, lump-sum payment scheduled at the end of a series of considerably smaller periodic payments. A balloon payment may be included in the payment schedule for a loan, lease, or other stream of payments.
Answers.com: A final loan payment that is significantly larger than the payments preceding it.
MSN Money: A final loan payment that is considerably higher than prior regular payments, in order to pay off the loan. You may have a balloon payment for a short-term loan that you anticipate refinancing.
_________________________
Take responsibility for your life.