WordNet (r) 3.0 (2006):

sync
    v 1: make synchronous and adjust in time or manner; "Let's
         synchronize our efforts" [syn: synchronize,
         synchronise, sync] [ant: desynchronise,
         desynchronize]

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

sync

   /sink/ (Or "synch") 1. To synchronise, to bring into
   synchronisation.

   2.  To force ("flush") all pending buffered
   disk writes to the disk.

   3. More generally, to force a number of competing processes or
   agents to a state that would be "safe" if the system were to
   crash, i.e. to checkpoint in the database sense.

   [Jargon File]

   (1994-11-11)


The Jargon File (version 4.4.7, 29 Dec 2003):

sync
 /sink/, vi.

    (var.: synch)

    1. To synchronize, to bring into synchronization.

    2. [techspeak] To force all pending I/O to the disk; see flush, sense 2.

    3. More generally, to force a number of competing processes or agents to a
    state that would be ‘safe’ if the system were to crash; thus, to checkpoint
    (in the database-theory sense).