model. In addition to its taxonomic organization, the Historical Thesaurus of English (2009) includes the date when each word came to have a given meaning. It has the novel and unique goal of "charting the semantic development of the huge and varied vocabulary of English". Different senses of a word are listed separately. For example, three difference senses of "debt" are listed in three different places in the taxonomy: A sum of money that is owed or due; a liability or obligation to pay Society Trade and Finance Management of Money Insolvency Indebtedness [noun] An immaterial debt; an obligation to do something Society Morality Duty or obligation [noun] An offence requiring expiation (figurative, Biblical) Society Faith Aspects of faith Spirituality Sin [noun] instance of Alphabetical Other thesauri and synonym dictionaries are organized alphabetically. Most repeat the list of synonyms under each word. Some designate a principal entry for each concept and cross-reference it. A third system interfiles words and conceptual headings. Francis March's Thesaurus Dictionary gives for liability: , each of which is a conceptual heading. The article has multiple subheadings, including Nouns of Agent, Verbs, Verbal Expressions, etc. Under each are listed synonyms with brief definitions, e.g. "Credit. Transference of property on promise of future payment." The conceptual headings are not organized into a taxonomy. Benjamin Lafaye's Synonymes français (1841) is organized around morphologically related families of synonyms (e.g. logis, logement), and his Dictionnaire des synonymes de la langue française (1858) is mostly alphabetical, but also includes a section on morphologically related synonyms, which is organized by prefix, suffix, or construction. Contrasting senses Before Roget, most thesauri and dictionary synonym notes included discussions of the differences among near-synonyms, as do some modern ones. Merriam-Webster's Dictionary of Synonyms is a stand-alone modern English synonym dictionary that does discuss differences. In addition, many general English dictionaries include synonym notes. Several modern synonym dictionaries in French are primarily devoted to discussing the precise demarcations among synonyms. Additional elements Some include short definitions. Some give illustrative phrases. Some include lists of objects within the category (hyponyms), e.g. breeds of dogs. Bilingual Bilingual synonym dictionaries are designed for language learners. One such dictionary gives various French words listed alphabetically, with an English translation and an example of use. Another one is organized taxonomically with examples, translations, and some usage notes. Information science and natural language processing In library and information science, a thesaurus is