Boot

Boot refers to “something that is given in addition to.” Boot is the money or other property which is added to an exchange to equalize the value of a trade.  

In the context of like-kind property under Internal Revenue Code Section 1031, it refers to cash or other property which does not qualify for the exchange and is taxed. For example, if a taxpayer sells a relinquished property for $150,000 and buys a replacement property for $120,000, the difference of $30000 is referred to as boot and is taxable.