Brandeis University has a helpful research guide on Yiddish resources. Note that database or digital resource links will probably not work. Instead, search the title of the resource in CLIO to get access.
Comprehensive Yiddish-English Dictionary
Including over 37,000 entries compiled by a team of expert Yiddish linguists, Comprehensive Yiddish-English Dictionary surpasses all its predecessors in the number of words and rich selection of idioms, examples of usage, and coverage of stylistic levels and dialect forms. The user-friendly entries include words for standard and literary as well as contemporary colloquial and conversational usage and a wide range of terms from all sources of Yiddish, including those of Hebraic-Aramaic, Slavic, and Romance as well as Germanic origin. The lexical corpus comes directly from the highly acclaimed Dictionnaire Yiddish-Français by Yitskhok Niborski and Bernard Vaisbrot, published by the Bibliothèque Medem in Paris in 2002. Augmented by an extensive user's guide, this volume is an indispensable resource for students, teachers, translators, and readers of Yiddish.