The Collaborative International Dictionary of English v.0.48:

University extension \U`ni*ver"si*ty ex*ten"sion\
   The extension of the advantages of university[3] instruction
   by means of lectures and classes at various centers.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

university extension
    n 1: an educational opportunity provided by colleges and
         universities to people who are not enrolled as regular
         students [syn: extension, extension service,
         university extension]