What does ‘floor limit’ mean?

A floor limit is basically a threshold of an amount set by a store for example, which requires authorization if you are willing to pay with your credit card. MasterCard and Visa are two such examples, which, if you do your shopping at certain stores, there will be required an authorization in order for your card to be accepted. So, for example if you walk in to a store where the floor limit is set at $300, anything you are willing to purchase above this value will need an authorization from the issuer banking institution.