Definition - What does Float mean?
A float is the time frame between when a person deposits a check into their bank account and when the money actually shows up for use by the depositor. The float is a legal requirement of banks that allow the bank the opportunity to determine whether or not the check is going to clear or if there are any problems with the check so that there are no outlays by the bank that will not be covered, such as if there is not enough money in the account to clear the check.
Justipedia explains Float
Banks are legally obliged to put a float in action due to the many different ways in which a check may not be good, including where laws have been broken by the issuance of the check. An example of this is uttering and publishing.