linguist who began the most thorough dictionary of the Lithuanian language and whose extensive linguistic interests had an abiding influence on later generations of Baltic and Slavic linguists.

His etymological research, which occupied a considerable part of his professional interest, began around 1902 and was the subject of valuable articles over a period of two decades. His research of Lithuanian personal names (c. 1910) led him into the study of place-names. From them he was able to determine that the homeland of the Lithuanians and other Baltic peoples up to the 6th to 9th century AD had been just north of Ukraine around the Pripet River. In addition, he studied the chronological sequence of Slavic loanwords in the Baltic languages.

Būga began teaching in Russia in 1916, but after his return to Lithuania in 1920 he immediately began to prepare his ambitious Lietuvių kalbos žodynas (“Dictionary of the Lithuanian Language”), which was to be a comprehensive thesaurus that would include definitions, etymologies, histories of words, and notes on their geographic distribution. From 1922, however, he was burdened with teaching responsibilities at the newly founded University of Kaunas. By the time of his death, he had completed relatively little of his enormous lexicographic undertaking. Work has continued, however, and the dictionary will comprise 17 volumes.