The Free On-line Dictionary of Computing (19 January 2023):

Synchronous Dynamic Random Access Memory
SDRAM
Synchronous DRAM

    (SDRAM, Synchronous DRAM) A form of DRAM which
   adds a separate clock signal to the control signals.  SDRAM
   chips can contain more complex state machines, allowing them
   to support "burst" access modes that clock out a series of
   successive bits (similar to the nibble mode DRAM).

   (2007-05-08)