Source : Webster's Revised Unabridged Dictionary (1913)

University extension \U`ni*ver"si*ty ex*ten"sion\
   The extension of the advantages of university instruction by
   means of lectures and classes at various centers.

Source : WordNet®

university extension
     n : an educational opportunity provided by colleges and
         universities to people who not enrolled as regular
         students [syn: {extension}, {extension service}]