boot

Definition from Nolo’s Plain-English Law Dictionary

In a 1031 exchange, any property, liabilities, or money received that does not qualify for the exchange and is taxed. For example, if a taxpayer sells a relinquished property with a $100,000 gain and buys a replacement property for $10,000 less than the sales price of the relinquished property, he has $10,000 boot.

Definition provided by Nolo’s Plain-English Law Dictionary.