Post by Peter T. DanielsPost by DingbatPost by Yusuf B GurseyAn early term for Indo-European was Indo-German. Why "German"? Early form of German nationalism?
In German indogermanisch remains the standard scientific term.
https://en.wikipedia.org/wiki/Indo-European_languages
The term was coined by (you guessed it) German linguists, and since pretty much every linguist was German in that time, no one really suggested another name for a pretty long time. In the German language, Germanen and germanisch refer to the ancient Germanic peoples, not to modern Deutschland. The IE family does stretch from India to Germanic if you are concentrating just on the north-south dimension.
https://www.quora.com/What-does-Indo-German-mean-and-why-it-is-called-Indo-European-today
And Celtic wasn't included in the initial statements by Jones and Bopp.
Actually Jones does mention "the Gothic and the Celtic" as probably
part of the family.
Post by Peter T. DanielsI don't recall seeing "Indo-German" in English-language publications. Max Mueller
used "Aryan."
I don't recall it either. OED has three 19th-century citations of
"Indo-German", along with five of "Indo-Germanic" -- none of them by
anyone well-known.
Their etymological note on the origins of the term (in German) is
perhaps relevant here. The earliest use they find is in Klaproth's
_Asia Polyglotta_ (1823), where "it seems to have been a kind of
abbreviation of the expression (used by him in an earlier work)
‘die grosse Indisch-Medisch-Sclavisch-Germanische Völkerkette...'
naming the two extreme members of the ethnological ‘chain’. When
Celtic was shown to be a still more extreme member of the same series, ‘indogermanisch’ lost its appropriateness, and some scholars tried
to substitute indokeltisch, ‘Indo-Celtic’, in French indo-celtique, while others, as Bopp in his Vergleichende Grammatik, gave preference to the more comprehensive indoeuropäisch,.... But the employment of ‘indogermanisch’
on the title-page of Pott's Etymologische Forschungen auf dem Gebiete der indogermanischen Sprachen (1833–36) popularized this term in Germany, whence under the influence of German textbooks, or of teachers trained in Germany,
it came into English use, and was, in the 19th c., probably more used than ‘Indo-European’.)"
"Indo-European" is slightly older, apparently coined by Thomas Young
("The Last Man Who Knew Everything") in 1813.