A synthetic language (also known as fusion) is, of morphological typology , a language being defined by the combination of morphemes language. All languages of this category belong to the group of inflected languages.

The typology is a synthetic morphological subgroup of inflected languages.

Synthetic languages oppose agglutinative languages because they pose a syncretism pushed into their minimum meaningful elements: a single shape, indecomposable, apply to several semantic elements (or grammatical) identifiable. The Latin or Greek are classic examples of inflectional type.

German provides an example as to contemporary languages. Der Mann ist mein Lehrer ("The man is my teacher"), Article der indicates both the set (as opposed to the indefinite article), the singular , the masculine and the nominative. It is the same in the Slavic languages. Romance languages are also part of this category of language.