Meaning cat's elbow (even though they don't have any), how did the German word katzenellenbogen become a fairly common surname?

The name comes from the old medieval county, and now small German city, Katzenelnbogen, derived from "Cattimelibocus," apparently a Roman name for a German tribe. A prolific family of rabbis living in the area took the location's name as a surname.

There was, in fact, an art historian by this name.


https://en.wikipedia.org/wiki/Katzenelnbogen

You're right about the rabbis, when I googled nearly every name was one, except our neighbours who shortened it to Bogen.
So what they call 'Hobson-Jobson', where a foreign word is transformed into something familiar. Fascinating result, they probably saw the humour in it, German or not ;)

I am not too sure about that German sense of humour in this case. Though it is correct that many Jews adopted citynames when they were forced to choose a surname, it must be taken into account that especially in Prussia it often was a city official who chose a name for them, and as this other site points out, the poorer Jews usually were given slightly ridiculous,derogatory or to say the least "funny" names. Many a Prussian official may have chosen the name Katzenellenbogen for his Jewish customer more by "Schadenfreude" (malicious pleasure)than by geographical wisdom.

[freepages.genealogy.rootsweb.com/~hjohnson/surnamehistory.html#mozTocId135697 -- no longer online]

I thought the same thing, but was more referring to the existence of such a name at all, before adopted as a surname. What they did with it afterwards is clearly a different matter and would depend whether the family chose the name or it was imposed on them. But the name appeared to have been much older than the surname as many jews didn't use surmnames until made to by law.

The length of the word Katzen-ellen-bogen is also somewhat funny.This way of creating very long compounds occasionally fires back on the Germans e.g. in titles such as Reichs-ober-gruppen-führer,SS-ober-gruppen-führer, Ober-sturm-bahn-führer,Sturm-gruppen-führer. Very solemn, but also a little ridiculous. During the war people in the occupied territories created their own imitations of such "long compounds" . E.g.Schweine-puppe-fleisch for pork.
Literally pig-butt-meat. Puppe does not really exist in German but was created after a Flemish dialectword.

When my husband and I were in grad school in Art History, we sent around an April Fool's Day memo announcing the formation of a departmental bowling team. In the memo, we noted that the proposed team name, "Kunstgeschichtlichekegelbahngruppe" (an entirely fabricated term meaning "History of Art Bowling Team") probably wouldn't fit on the shirts.

I'm sure that the Germans must have a more efficient term for "bowling team," but we were playing both on the hysteria of Art History grad students regarding their German exams and the frequent occurrence of lengthy compound nouns in German.