The Free On-line Dictionary of Computing (30 December 2018):

virtual circuit
switched virtual circuit

    A connection-oriented network service which
   is implemented on top of a network which may be either
   connection-oriented or connectionless (packet switching).

   The term "switched virtual circuit" was coined needlessly to
   distinguish an ordinary virtual circuit from a permanent
   virtual circuit.  (One of the perpetrators of this confusion
   appears to be ["Networking Essentials", 1996, Microsoft Press,
   ISBN 1-55615-806-8], a book aimed at people preparing for the
   MCSE exam on LANs and WANs).

   Not to be confused with switched virtual connection.

   (2001-10-26)