Slavic adj.

"one of the people who inhabit most of Eastern Europe," late 14c., Sclave, from Medieval Latin Sclavus (c. 800), from Byzantine Greek Sklabos (c. 580), from a shortening of Proto-Slavic *sloveninu "a Slav," which is probably related to *slovo "word, speech," which suggests the name originally identified a member of a speech community (compare Old Church Slavonic Nemici "Germans," related to nemu "dumb;" Greek heterophonos "foreign," literally "of different voice;" and Old English þeode, which meant both "race" and "language").

Max Vasmer, the authority for Slavic etymologies, rejects a connection to *slava "glory, fame," which, however, influenced Slav via folk etymology. This word is the -slav in personal names (such as Russian Miroslav, literally "peaceful fame;" Mstislav "vengeful fame;" Jaroslav "famed for fury;" Czech Bohuslav "God's glory;" Latinized Wenceslas "having greater glory"), and is perhaps from PIE root *kleu- "to hear."

The reduction of scl- to sl- is regular in English (compare slate). In late 18c. and early 19c. The spelling Slav is by 1866; in English it also was spelled Slave, influenced by French and German Slave. As an adjective, belonging to or characteristics of Slavs, from 1876.

Middle English -ik, -ick, word-forming element making adjectives, "having to do with, having the nature of, being, made of, caused by, similar to," from French -ique and directly from Latin -icus or from cognate Greek -ikos "in the manner of; pertaining to." From PIE adjective suffix *-(i)ko, which also yielded Slavic -isku, adjectival suffix indicating origin, the source of the -sky (Russian -skii) in many surnames. In chemistry, indicating a higher valence than names in -ous (first in benzoic, 1791).

In Middle English and after often spelled -ick, -ike, -ique. Variant forms in -ick (critick, ethick) were common in early Modern English and survived in English dictionaries into early 19c. This spelling was supported by Johnson but opposed by Webster, who prevailed.