English abstract

Dictionary definitions are made:
1) by isometry (a word defined by a synonym);
2) by expansion (a word defined by a metalinguistic paraphrase);
3) by reduction (a metalinguistic paraphrase defining a word).

This last is typical of the crossword puzzle, but was also used incidentally by Robert Estienne when he turned his Latin-French dictionary into a French-Latin version. The explanation of a Latin word inexistent in French then became the entry by which one found these same Latin words. This principle was extensively used by early English lexicographers, who developed entry through English definitions to "hard", Latinate, words.