The YIVO Institute for Jewish Research probably has the most comprehensive Yiddish dictionary collection that exists anywhere in the world today. A complete list can be found on the YIVO website (see the link below). It gives an excellent idea of the range of Yiddish dictionaries that have been published from the late 19th century onwards. From the website: "There are over 100 Yiddish dictionaries in the YIVO Library. The following list of available dictionaries is sorted alphabetically according to type of dictionary (see last column of table) and date of publication. Subject headings include: Academic Terminology, Etymological, Foreign Words in Yiddish, Humorous, Industrial and Commercial Terms, Medical Terminology, Political Terms, Proverbs, Scientific Terms, Technological Terms, Thesaurus, Words of Hebrew and Aramaic Origin. Languages: Multiple Languages Belorussian, Dutch, Encyclopedia, English, French, German, Hebrew, Hebrew/Aramaic, Japanese, Lithuanian, Polish, Russian, Spanish, Ukrainian."