Origin of the word slavic as per Wikipedia (citations not included):

The Slavic autonym *Slověninъ is usually considered a derivation from Proto-Slavic adjective svobъ ("oneself", "one's own"; derivative svoboda > sloboda also "freedom", "free settlement"), which derives from Indo-European *s(w)e/obh(o)- "a person or thing apart, separate", root *swobh "his/hers", meaning "all the members of an exogamic moiety > actual or potential affines/blood relatives”. It can be interpreted as "a tribe of the free, of their own people”. The word slovo ("word") and the related slava ("glory, fame, praise") and slukh ("hearing") originate from the Proto-Indo-European root *ḱlew- ("be spoken of, glory"), cognate with Ancient Greek κλέος (kléos "fame"), whence comes the name Pericles, Latin clueo ("be called”).

Unfortunately, that is not the only issue with this post but the few top responses I saw pretty much cover it all.