Source : Webster's Revised Unabridged Dictionary (1913)

Police power \Police power\ (Law)
   The inherent power of a government to regulate its police
   affairs.

   Note: The term police power is not definitely fixed in
         meaning. In the earlier cases in the United States it
         was used as including the whole power of internal
         government, or the powers of government inherent in
         every sovereignty to the extent of its dominions (11
         Peters (--U. S.) 102). The later cases have excepted
         from its domain the development and administration of
         private law. Modern political science defines the power
         as a branch of internal administration in the exercise
         of which the executive should move within the lines of
         general principles prescribed by the constitution or
         the legislature, and in the exercise of which the most
         local governmental organizations should participate as
         far as possible (--Burgess). Under this limitation the
         police power, as affecting persons, is the power of the
         state to protect the public against the abuse of
         individual liberty, that is, to restrain the individual
         in the exercise of his rights when such exercise
         becomes a danger to the community. The tendency of
         judicial and popular usage is towards this narrower
         definition.