An agglutinative language is a language in which the words are
formed by gluing morphemes together. This term was introduced by
Wilhelm von Humboldt 1836 to classify languages from a
morphological point of view. Agglutinative languages are the
most common form of synthetic language, and are usually highly
inflected. The name was derived from the Latin verb agglutinare,
which means "to glue together". The opposite of a synthetic
language is an analytic, or isolating language. Synthetic
languages which are not agglutinative are called fusional
languages; they combine morphemes by "squeezing" them together,
often changing the morphemes drastically in the process.
"Agglutinative" is sometimes used as a synonym for synthetic,
although it technically is not. When used in this way, the word
embraces fusional languages and inflected languages in general.
It is also worth noting that the distinction between an
agglutinative and a fusional language is often not a sharp one.
Rather one should think of these as two ends