In
cycling, float is the degree to which you are able to rotate your feet on the
pedals along the horizonal plane (in other words, rotation around around the y axis or rotation on the tops of the pedals). This ability is normally represented in "
degrees of float". To be absolutely unable to rotate your feet would be to have zero float. Most
clipless pedals have somewhere between 4 and 8 degrees of float.
Some float is generally desired for anyone without absolutely perfect pedalling biomechanics, as it is easier on the knees.