Etymology ( ) is the study of the history of the form of words and, by extension, the origin and evolution of their semantic meaning across time. It is a subfield of historical linguistics, and draws upon comparative semantics, morphology, semiotics, and phonetics. For languages with a long written history, etymologists make use of texts, and texts about the language, to gather knowledge about how words were used during earlier periods, how they developed in meaning and form, or when and how they entered the language. Etymologists also apply the methods of comparative linguistics to reconstruct information about forms that are too old for any direct information to be available. By analyzing related languages with a technique known as the comparative method, linguists can make inferences about their shared parent language and its vocabulary. In this way, word roots in many European languages, for example, can be traced all the way back to the origin of the Indo-European language family. Even though etymological research originated from the philological tradition, much current etymological research is done on language families where little or no early documentation is available, such as Uralic and Austronesian. Etymology The word etymology derives from the Greek word (), itself from (), meaning "true sense or sense of a truth", and the suffix -logia, denoting "the study of". The term etymon refers to a word or morpheme (e.g., stem or root) from which a later word or morpheme derives. For example, the Latin word candidus, which means "white", is the etymon of English candid. Relationships are often less transparent, however. English place names such as Winchester, Gloucester, Tadcaster share in different modern forms a suffixed etymon that was once meaningful, Latin castrum 'fort'. Methods Etymologists apply a number of methods to study the origins of words, some of which are: Philological research. Changes in the form and meaning of the word can be traced with the aid of older texts, if such are available. Making use of dialectological data. The form or meaning of the word might show variations between dialects, which may yield clues about its earlier history. The comparative method. By a systematic comparison of related languages, etymologists may often be able to detect which words derive from their common ancestor language and which were instead later borrowed from another language. The study of semantic change. Etymologists must often make hypotheses about changes in the meaning