If you are looking for Yiddish dictionaries for some specific reasons, this list on the YIVO website helps you.
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