\Syn-\ [Gr. sy`n with.] A prefix meaning with, along with, together, at the same time. Syn- becomes sym- before p, b, and m, and syl- before l.
1. Synchronous idle.
2. A syntactic specification language for COPS.
["Metalanguages of the Compiler Production System COPS", J. Borowiec, in GI Fachgesprach "Compiler-Compiler", ed W. Henhapl, Tech Hochs Darmstadt 1978, pp. 122-159].
Webster's 1913 Dictionary