degree of freedom  
—n  
1.  physics one of the minimum number of parameters necessary to describe a state or property of a system 
2.  one of the independent components of motion (translation, vibration, and rotation) of an atom or molecule 
3.  chem See also phase rule one of a number of intensive properties that can be independently varied without changing the number of phases in a system 
4.  statistics one of the independent unrestricted random variables constituting a statistic 
degree of freedom
