Wikipedia
The Paemani (or Poemani or Caemani) were a tribe of Gallia Belgica, mentioned by Julius Caesar in his commentary of his Gallic Wars. They were one of a group of tribes listed by his local Remi informants as the Germani, along with the Eburones, Condrusi, Caeraesi (or Caeroesi), and Segni. These tribes are therefore referred to as the " Germani Cisrhenani", to distinguish them from Germani living on the east of the Rhine, outside of the Gaulish and Roman area.
Whether this meant that they actually spoke a Germanic language or not, is still uncertain, but it was claimed by Tacitus that these Germani were the original Germani, and that the term Germani had come to be used broadly, having once only referred to this one people. He also said that the descendants of the original Germani in his time were the Tungri, who had changed their name.
The Paemani are frequently associated with the present-day Famenne region of central Wallonia. The proposal that the name Famenne itself derives from Paemani is no longer widely accepted, but the region is thought to be one reasonable proposal for where they lived.
It has been argued that their name was actually the "Caemani". This was the spelling found in a paraphrase of Caesar by Orosius.
In later records, during the time of the Roman empire, the Paemani are no longer mentioned. The old districts of the Condrusi and the Caeroesi are thought to have kept their names into the Middle Ages.