Old' Church' Slavon'ic
the oldest attested Slavic language, an ecclesiastical language written first by Cyril and Methodius in a Bible translation of the 9th century and continued in use for about two centuries. It represents the South Slavic, Bulgarian dialect of 9th-century Salonika with considerable addition of other South and West Slavic elements. Abbr.:
OCS Also called Old' Church' Slav'ic, Old Slavic, Old Slavonic.
Cf. Church Slavic.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.