DuckCorp Dico

Found one definition

1.                 From The Free On-line Dictionary of Computing (19 January 2023):
                   
   
   
                   
                     
   Single Edge Contact Cartridge
   SEC
   SECC
      <hardware> (SEC, SECC) The cased daughterboard housing
      Intel's Pentium II, Pentium III, and Xeon
      microprocessors.
      A SECC fits into a Slot 1 or Slot 2 connector.
      [SECC 2?]
      (1999-08-05)