Ancient Belgian is a hypothetical extinct Indo-European language, spoken in Belgica (northern Gaul) in late prehistory. It is often identified with the hypothetical Nordwestblock. While it remains a matter of controversy, the linguist Maurits Gysseling — who himself attributed the term to SJ De Laet — hypothesised a Belgian that was distinct from the later Celtic and Germanic languages. According to the theory, which was further elaborated by Hans Kuhn and others, traces of Belgian can be found in certain toponyms such as South-East-Flemish Bevere, Eine, Mater and Melden.
Overview
The borders of the Belgian Sprachraum are made up by the Canche and the Authie in the south-west, the Weser and the Aller in the east, and the Ardennes and the German Mittelgebirge in the south-east. It has been hypothetically associated with the Nordwestblock, more specifically with the Hilversum culture.
The use of the name Belgian for the language is to some extent supported by Caesar's De Bello Gallico which mentions that the Belgae and the Galli spoke different languages. It is furthermore supported by toponyms in present-day Belgium which, according to the linguist Hans Kuhn, point at the existence of an Indo-European language distinct from the Celtic and Germanic languages.
Proponents of the Belgian language hypothesis also suggest that it was influenced by Germanic languages during a first, early "germanicization" in the third century BC – as distinct from the Frankish colonization in the fifth to the eighth century. For example, the Germanic sound shifts (p → f, t → th, k → h, ǒ → ă) have affected toponyms which supposedly have a Belgian-language origin.
Characteristic of Belgian said to include the retention of p after the sound shifts (a trait that it shared with the Lusitanian language). Names of bodies of water ending in -ara (as in the name for the Dender), -ănā or -ǒnā as in Matrǒnā (Marne river and also the nowadays Mater) and settlement names ending in -iǒm are supposedly typically Belgian as well.
According to Gysseling, traces of Belgian are still visible. The diminutive suffix -ika, the feminizing suffixes -agjōn and -astrjō and the collective suffix -itja- have been incorporated in Dutch, sometimes very productively. In toponymy, apa, poel, broek, gaver, drecht, laar and ham are retained as Belgian loanwords.