There are several Yiddish online glossaries for those who want to learn more about the Yiddish language and culture.

You might be surprised to discover that many of the words in these glossaries will look familiar. Although primarily Jews throughout the world speak Yiddish, some of its vocabulary has made its way into English vernacular. The words klutz, schmaltzy and maven have their roots in Yiddish. How many of us have noshed on a bagel or schmoozed with friends? Or maybe you recognize the exclamations of Jewish grandmothers on television and in the movies, Oi gevald! Oi Vai! So even if you do not know all the fine points of this language, you likely have mastered a bisel (little) Yiddish.
According to YourDictionary.com Yiddish is spoken primarily by Eastern European Jews, also known as Ashkenazi Jews, and their descendants. Its origin can be traced to the tenth century and has its roots in High German although throughout time borrowed from Hebrew, Russian, Polish and other languages. While spoken throughout the world, it is unique because it is written with the Hebrew alphabet.
An estimated three million people speak Yiddish worldwide with the largest concentration of Yiddish speakers in the United States (178,945) and Israel (215,000) Ethnologue. Speakers of Yiddish can also be found in Argentina, Brazil, United Kingdom, Russia, Canada, Ukraine, Belarus, Moldova, Lithuania, Belgium, Germany, Switzerland, Sweden, Poland and Australia.
Despite its relatively small pool of speakers, Yiddish is a well-documented language. There are several dictionaries available right here at YourDictionary.com:
To gain greater insight into a language, it helps to know the customs and traditions of its speakers. Many websites offer insight into Yiddish and Jewish culture. One such site is Judaism 101 where you can learn more about Jewish holidays and traditions.
A great way to master a language is to fall in love in it. Find out about Yiddish romance in articles about Jewish Dating and wedding traditions on Jewish Wedding Traditions. You can read about traditional baby-naming customs in “A Brief Lesson in Hebrew and Yiddish Names and How They are Chosen” Jewish Baby Names. To gain insight into the contemporary issues that affect Yiddish speakers, take a look at The Forward The Forward and its Yiddish-speaking counterpart Yiddish Forward.
There are many answers to the question, “Is there an online Yiddish dictionary?” Internet resources abound for those who want to know more about this language. Whether you want to discover how to say sweetheart or the correct spelling for the word shtick, there is a wide variety of Yiddish dictionaries available for your use.