The glossonym type giudeo-italiano is of academic and relatively late coinage. In English, Judeo-Italian was first used by Lazaro Belleli in 1904 for his article Judæo-Greek and Judæo-Italian in the Jewish Encyclopedia (vol. 7, 310-313), describing the languages of the Jews of Corfu. In Italian, Giuseppe Cammeo referred to a Gergo giudaico-italiano in his 1909 article Studj dialettali (Vessillo Israelitico 57 (1909); the term first appears on p. 169). That same year, Umberto Cassuto used the term giudeo-italiano, in the following:
Actually, while the existence of a Judæo-German dialect is universally known, almost nobody beyond the Alps suspects that the Italian Jews have, or at least had, not to say a dialect of their own, but at least a way of speaking with peculiar features. True, in practice its importance, limited to the everyday use of some thousand people, is almost nothing versus that of Judæo-German, spoken by millions of individuals that often do not know any other language, and has its own literature, its own journalism, its own theater, and thus, almost the importance of a real language... It is almost nothing, if you will, even compared with other Jewish dialects, Judæo-Spanish for instance, that are more or less used literally; all this is true, but from the linguistic point of view, Judæo-German is worth as much as Judæo-Italian [giudeo-italiano], to name it so, since for the glottological science the different forms of human speech are important in themselves and not by its number of speakers or the artistic forms they are used in. Moreover, a remarkable difference between Judæo-German and Judæo-Italian [giudeo-italiano], that is also valuable from the scientific point of view, is that while the former is so different from German as to constitute an independent dialect, the latter by contrast is not essentially a different thing from the language of Italy, or from the individual dialects of the different provinces of Italy...
...It was natural that the Judæo-Italian jargon [gergo giudeo-italiano] would disappear in a short while.
One of the most accessible ways to view the Judeo-Italian language is by looking at translations in biblical texts such as the Torah and Hagiographia. Today, there are two locations, the Oxford Bodleian Library and the Jewish Theological Seminary in New York, in which these translated texts can be found.
Historically, Italian Jews referred to their vernaculars as "La`az" (לעז), Hebrew for "foreign language" (i.e., specifically, "non-Hebrew language"). The Italian Jewish rite is sometimes called minhag ha-lo'azim, and linguists use lo'ez as a description of words of Romance origin in Yiddish. This may be connected with the Germanic use of the word wälsch (literally, "foreign") for Romance peoples and languages (as in "Welsh", "Walloon" and "Wallachian"): the Italian and Sephardic Hebrew script for Torah scrolls is known as "Velsh" or "Veilish".
In 1587, David de Pomi uses the word "italiano" in reference to the Italian glosses in his trilingual dictionary. The Hebrew title of the 1609 Venice Haggadah uses the word "italiano" for the language of Leone Modena's translation (u-fitrono bi-leshon iṭalyano; ופתרונו בלשון איטליאנו).
Other historic descriptions are "Latino" and "Volgare", both of which were commonly used in the Middle Ages to mean Italian in general.
After the institution of the Ghetto forced Jewish communities throughout Italy into segregation, the term ghettaiolo was identified with local Jewish varieties of regional dialects.
Another native name type is giudeesco (e.g., Judeo-Florentine iodiesco; < *IUDÆĬSCU[M], or an assimilation of the hiatus /aˈe/ *giudaesco < *IUDAĬSCU[M]).
The neologism Italkian was coined in 1942 by Solomon Birnbaum (see References), who modelled the word on the modern Hebrew adjective ית-/אטלקי italki(t), “Italian”, from the middle Hebrew adjective איטלקי (< ITALICU[M]), “Italic” or “Roman”.
Influence on Yiddish
According to some scholars, there are some Judeo-Italian loan words that have found their way into Yiddish. For example, the word in Judeo-Italian for "synagogue" is scola, as opposed to "school," which is scuola. The use of words for "school" to mean "synagogue" dates back to the Roman Empire. The Judeo-Italian distinction between scola and scuola parallels the Standard Yiddish distinction between shul/shil for 'synagogue' and shule for 'school'. Another example is iente, from the Judeo-Italian yientile, as differentiated from the standard Italian gentile, meaning 'noble'.
All of the spoken Judeo-Italian varieties used a unique (among Jewish languages, although there are arguably parallels in Jewish English usage) combination of Hebrew verb stems with Italian conjugations (e.g., "אכלר akhlare", to eat; "גנביר gannaviare", to steal; "דברר dabberare", to speak; "לכטיר lekhtire", to go). Similarly there are abstract nouns such as "טובזה tovezza", goodness.
Also common are lexical incorporations from Hebrew, particularly those applicable to daily life. Terms from other Jewish languages such as Yiddish and Judaeo-Spanish were also incorporated.
It was claimed by Cassuto that most Judeo-Italian dialects reflect the Italian dialect of places further to the south, due to the fact that since the expulsion of the Jews from the Kingdom of Naples the general direction of Jewish migration in Italy has been northward.
The Judeo-Italian language can be found in a Haggadah, a Jewish prayer book typically used during a seder. Judeo-Italian is represented in this 1716 Venice Haggadah. 
Library of Congress/ISO information
"Italkian" is not used by the Library of Congress as a subject heading, neither does it figure as a reference to Judeo-Italian. The authorized subject heading is "Judeo-Italian language". Subheadings are:
Judeo-Italian language: Glossaries, vocabularies, etc.
Judeo-Italian language: Grammar.
Judeo-Italian language: Italy Livorno Glossaries, vocabularies, etc.
Judeo-Italian language: Texts.
The subject reference is: Judæo-Italian dialect. LC-MARC uses the following language codes :
Judeo-Italian Assigned collective code [ita] (Italian).
^Infatti, mentre è universalmente nota l’esistenza di un dialetto giudeo-tedesco, quasi nessuno sospetta oltr’alpe che gli ebrei italiani abbiano pure, o almeno abbiano avuto, non dirò un loro dialetto, ma almeno una loro parlata con peculiari caratteri. Certo, praticamente l’importanza di essa, limitata all’uso quotidiano di poche migliaia di persone, è pressoché nulla di fronte a quella del giudeo-tedesco, il quale è parlato da milioni di individui che bene spesso non conoscono altra lingua, ed ha una propria letteratura, un proprio giornalismo, un proprio teatro, sì da assumere quasi l’importanza di una vera e propria lingua a sé … è pressoché nulla, se si vuole, anche a paragone di altri dialetti giudaici, del giudeo-spagnuolo ad esempio, che sono più o meno usati letterariamente; è vero tutto questo, ma dal punto di vista linguistico tanto vale il giudeo-tedesco, quanto il giudeo-italiano, se così vogliamo chiamarlo, giacché di fronte alla scienza glottologica le varie forme del parlare umano hanno importanza di per sé e non per il numero di persone che le usano o per le forme d’arte in cui vengono adoperate. Piuttosto, una notevole differenza fra il giudeo-tedesco e il giudeo-italiano, che ha valore anche per il riguardo scientifico, è che, mentre quello è tanto diverso dalla lingua tedesca da costituire un dialetto a sé stante, questo invece non è essenzialmente una cosa diversa dalla lingua d’Italia, o dai singoli dialetti delle varie provincie d’Italia … ; 256: … era naturale che il gergo giudeo-italiano in breve volger di tempo sparisse… (Umberto Cassuto “Parlata ebraica.” Vessillo Israelitico 57 (1909): 255-256)
Birnbaum, Solomon. "Jewish Languages", in Essays in Honour of the Very Rev. Dr. J. H. Hertz, Chief Rabbi of the United Hebrew Congregations of the British Empire, on the Occasion of His Seventieth Birthday, September 25, 1942 (5703). Ed. I. Epstein, E. Levine, C. Roth. London, E. Goldston, . 51-67 (63, 67).
Ferretti Cuomo, Luisa. "Italchiano versus giudeo-italiano versus 0 (zero), una questione metodologica", in Italia: studi e ricerche sulla storia, la cultura e la letteratura degli Ebrei d'Italia 3.1-2 (1982): 7-32.
Fortis, Umberto. La parlata degli ebrei di Venezia e le parlate giudeo-italiane. La Giuntina, 2006. ISBN88-8057-243-1.
Fortis, Umberto and Zolli, Paolo, La parlata giudeo-veneziana: Assisi/Rome 1979 ISBN88-85027-07-5
Gold, David L. "The Glottonym Italkian", in Italia: studi e ricerche sulla storia, la cultura e la letteratura degli Ebrei d'Italia 2.1-2 (1980): 98-102.
Mayer Modena, Maria Luisa, “Le parlate giudeo-italiane”, in Storia d'Italia. Gli ebrei in Italia, a cura di Corrado Vivanti, vol. II, Dall'emancipazione a oggi, Einaudi, Torino 1997, pp. 939–963.