ekstensio

Ekstensio is a word corresponding to the English term "extension," used as a cognate or variant form in various languages and technical contexts. It denotes the action of extending, the state of being extended, or the part that extends, and appears in disciplines ranging from mathematics and logic to engineering and computing.

In philosophy and linguistics, the related notion of extension refers to the set of objects to which a term or concept applies; contrastingly, intensional aspects concern the properties or rules that determine membership. In mathematics, extension-related concepts include field extensions, set-theoretic extensions, and the extension of functions or structures. In computing, "extension" commonly describes add-on modules, browser or file extensions that expand functionality, and the practice of extending software interfaces or formats. In architecture and engineering, an extension is an addition to an existing structure.

Etymologically, the word derives from the Latin extensio and is part of a family of related terms in many European languages. As a lexical item it may also appear as a trade name, project title, or surname. Usage and precise meaning depend on disciplinary conventions, and in technical writing the term is typically clarified by context to avoid ambiguity.