"The Lithuanian-Latvian-Latgalian Dictionary" (hereinafter — "the LLL dictionary") has been compiled on the basis of "Lthe Lithuanian Language Written Sources Frequency Dictionary" ("Dažninis rašytinės lietuvių kalbų žodynas" , hereinafter — "the Frequency dictionary;" comp. by Utka A., Kaunas, VDU, 2009;)). It consists of 42,061 headwords based on the corpus of one million word usages. For the development of the LLL dictionary about a quarter of this dictionary has been used, i.e the word nests of the first 10,000 words.
The LLL dictionary contains 4,686 nouns, 3,138 verbs, 1,385 adjectives, 38 pronouns, 82 numerals, 549 adverbs, 26 prepositions, 23 conjunctions 23, 34 particles and 39 interjections of the Lithuanian language; all of them have been translated into Latvian and Latgalian.
The word meanings in the Latvian language have been harmonised with the counterparts of the corpus of the Frequency dictionary; they do not always coincide with the meanings of the Lithuanian-Latvian Dictionary as well as with those of the Contemporary Lithuanian Language Dictionary (Dabartinės lietuvių kalbų žodynas;). The main differences are of three kinds: a) a set of meanings of polysemic words in the corpus is generally less than that in the dictionaries mentioned; b) hierarchy of meanings of polysemic words differs; c) specific sectoral terms appear.
The meanings in the Latgalian language have been adjusted to the meanings of the Latvian and Lithuanian language words by respecting the key Latgalian normative and lexicographic sources (P. Strods "Pareizraksteibas vōrdneica" ["Spelling Dictionary"] (1933), M. Bukšs, J. Placinskis "Latgaļu volūdas gramatika un pareizraksteibas vōrdneica" ["Latgalian Grammar and Spelling Dictionary"] (1973), "Latgalīšu pareizraksteibys nūsacejumi" ["Latgalian Spelling Rules"] (2008), etc.). Besides the translation of the meanings it has been tried to determine the stylistic and expressive nuances of the Latgalian words, to show their territorial restriction and historical variability, thus carrying out the current standardisation of the Latgalian written (or literary) language. The most frequently used noun diminutives being derived occasionally have been added.
The constituent parts of the entries of the LLL dictionary:
• A headword from the corpus of the Frequency dictionary;
• The accentuated version of the same word (with grammatical and stylistic reference where necessary; for verbs the present and past tense forms of the third person have been shown);
• Morphological characterisation of a word (a part of speech, gender);
• A group of accentuation of nouns and adjectives;
• Usage frequency of a word in the corpus of the Frequency dictionary;
• Translation into Latvian of the meanings checked in the corpus;
• Semantic counterparts in the Latgalian language (with normative additions as to usage restrictions) to the meanings of the Latvian and Lithuanian language words;
Diminutives of nouns.
• Lietvārdu deminutīvi.
Compilers of the LLL dictionary: Prof. Dr. philol. L. Leikuma, Mg. philol. L. Bernāne and Mg. philol. J. Cibuļs (Rēzekne, Latvia), Prof. Dr. philol. A. Butkus, Mg. philol. V. Butkienė and Mg. philol. K. Vaisvalavičienė (Kaunas, Lithuania), Dr. philol. I. Sperga (Riga, Latvia).