In linguistics, a conservative form, variety, or feature of a language or dialect is one that has changed relatively little across the language's history, or which is relatively resistant to change. It is the opposite of innovative, innovating, or advanced forms, varieties, or features, which have undergone relatively larger or more recent changes. Furthermore, an archaic form is not only chronologically old (and often conservative) but also rarely used anymore in the modern language, and an obsolete form has fallen out of use altogether. An archaic language stage is chronologically old, compared to a more recent language stage, while the terms conservative and innovative typically compare contemporary forms, varieties or features.
A conservative linguistic form, such as a word or sound feature, is one that remains closer to an older form from which it evolved than cognate forms from the same source. For example, the Spanish word caro /'kaɾo/ and the French word cher /ʃɛʁ/, both adjectives meaning 'dear' or 'beloved', similarly evolved from the Latin word cārum ['ka:rum ~ -ɾũː] (Proto-Romance */ˈka.ru/). The Spanish word, which is more similar to the common ancestor, is more conservative than its French cognate, which is more innovative.