When Julius Caesar and the Romans attacked the region that is now known as Belgium, they found this land populated by a Celtic tribe named ‘Belgae’. The Romans dubbed their new province Gallia Belgic. When it comes to determining the meaning of the name Belgae, Julius Pokorny (1887 -1970), an Austrian linguist, traced the root word of ‘belgae’ in Gaulish from Proto Indo European (PIE) which is really concealed Sanskrit. (The region that we now know as Belgium was during the times of Julius Caesar part of the Gaul territory which included France and Luxembourg, and parts of Switzerland, Italy, Netherlands and Germany).
According to Pokorny, the word Belgae stems from PIE (again read Sanskrit!) ‘bhelgh-‘ and ‘bhelgh. In PIE ‘Bhelgh-‘ means to swell up. Some others who disagree with Pokorny say that Belgae stems from the Anglo-Saxon verb, ‘belgan’, meaning ‘to swell up, or to be angry’, sometimes also translated as ‘swell up with anger’.
Either ways the root word here really is the Sanskrit ‘brih’ (बृह्) which means ‘to increase in size’ or ‘thicken’. Unlike Sanskrit, PIE is a reconstructed language which has been engineered from various ancient languages. It is Sanskrit therefore rather than PIE which is a powerful instrument in decoding all ancient texts and inscriptions found around the world.
Those who have argued that the Anglo Saxon ‘belgen’ means both ‘swell up and angry’ must know that in Sanskrit ‘brih’ (बृह्) means to ‘swell up’, and ‘bhurni’ (भूर्णि) means ‘angry’. The Anglo Saxon ‘belgen’ is really an amalgamation of these two distinct Sanskrit root words.
The now extinct Gaulish and Celtic languages which the ancestors of the Belgae tribes spoke have a remarkable similarity to Sanskrit. For example in Gaulish the word ‘bel’ means ‘white’. Some scholars have put forth the view that the name ‘Belgae’ itself is derived from ‘bel’. What is of interest is the in Sanskrit too the word ‘balaksh’ (बलक्ष) means ‘white’.
Another example is the Gaulish word ‘karnito’ There is a famous Umbrian* Gaulish inscription: ‘Ateknati Trutikni karnitu artuaś Koisis Trutiknos’. This has been translated as ‘Koisis son of Drutos, has built the tomb of Ategnatos son of Drutos’. However, the translation is not accepted as perfect.
But what is accepted is that the word ‘Karnitu’ in the inscription means ‘to do’. It is also accepted that it stems from the Sanskrit ‘karoti’ (करोति), the root word being ‘Kr’ (कृ). Similarly the word ‘Trutikni’ translated as ‘Son of Truit or Druit’ may not be that at all. ‘Truit-kni’ may have more to do with the Sanskrit word ‘Putra’ which means ‘son’, and so on.
The word ‘Karnitu’ appears in another Gaulish inscription: ‘Pelkui pruiam teu karite, isos kalite palam’Here too the word ‘karite’ is translated as ‘do’. ‘Teu’ is also originates from Sanskrit ‘dev’ meaning ‘god’.
The other words in the inscription may also be distortions of Sanskrit words. For example: ‘Palam’ may be a distortion of Sanskrit ‘phalam’ meaning ‘reward’. ‘Pelkui’ may be linked to ‘palukshi’ means ‘fire’, ‘pruiam’ to ‘parma’ which means ‘highest’, ‘kalite’ to Sanskrit ‘kalita’ which most often means ‘made’ but also ‘separated’ and so on.
*It is interesting that the Umbria, which was a part of the Gaul territory is said to gets its name from the name of a tribe called ‘Ombri’ – its meaning is ‘people of thunderstorm’. In Sanskrit and Sanskrit derived languages the word ‘Ambar’ (अम्बर) means ‘sky’, ‘ambuda’ (अम्बुद) means ‘cloud’ and ‘abhriya’ (अभ्रिय) means ‘thunder’.
Here is a link to a Gaulish-English Glossary. Where ever the source word is mentioned as Indo-European (IE), you will find the word in a Sanskrit dictionary.