ciao and slave

Who knew that Italian ciao was a variation of schiavo "(I am your) servant" from medieval Latin sclavus "slave".

slave was borrowed from Old French esclave, which is related to the Latin sclavus. The Latin word was borrowed into English as Slav.

Further etymology of sclavus is uncertain. In my previous post I write that Slav and slave seem to be derived from Proto-Slavic *slovo "word" or *slava "fame, glory" but I think I was wrong. The OED says Old Slavic Slovēne is supposed to be derived from slovo, but is it really? The whole thing is a bit of a muddle.

etiquette and stigma

Proto-Indo-European *steig- "to stick" became Proto-Germanic *stikkēn "to be stuck" (AHD) and Old Low German stekan. This was borrowed into Old French as estiquer "to stick, fix", becoming estiquette then etiquet, borrowed into English as ticket. The French word was for ‘a little note, breuiate, bill, or ticket; especially such a one, as is stucke vp on the gate of a Court, signifying the seisure &c of an inheritance by order of iustice’ (Cotgrave).

The same Old French estiquette is also the source of English etiquette, which was first used to mean "The prescribed ceremonial of a court; the formalities required by usage in diplomatic intercourse." The semantic shift from "ticket, label" to "prescribed routine" presents no difficulty, the OED tells us.

In Greek the suffixed from *stig-yo- became στίζω stizō "to prick, puncture", and στίγμα stigma "mark".

*steig- is also found in raita and possibly tiger.