The second edition of A Dictionary of Tocharian B includes substantially all Tocharian B words found in regularly published texts, as well as all those of the London and Paris collections published digitally (digital publication of the Paris collection is still incomplete), and a substantial number of the Berlin collection published digitally. The number of entries is more than twenty per cent greater than in the first edition. The overall approach is decidedly philological. All words except proper names are provided with example contexts. Each word is given in all its various attested morphological forms, in its variant spellings, and discussed semantically, syntactically (where appropriate), and etymologically. New to the second edition is the assignment, where possible, of the examples of the word's use to their exact chronological period (Archaic, Early, Classical, Late/Colloquial). This dating provides the beginning of the study of the Tocharian B vocabulary on a historical basis. Included are also a reverse English-Tocharian B index and, another innovation to this edition, a general index verborum of Indo-European cognates. Douglas Q. Adams, PhD in Linguistics (1972), University of Chicago, is currently professor emeritus at the University of Idaho. His publications have been largely devoted to explorations of the lexicon and morphology of Proto-Indo-European and, particularly, of Tocharian. He was co-author with James P. Mallory of Queen's University, Belfast, of The Oxford Introduction to Proto-Indo-European and the Proto-Indo-European World (2006).