the Celts (inhabitants of Gaul)
Borrowed from Ancient Greek Κελτοί (Keltoí), Κέλται (Kéltai), Herodotus’ word for the Gauls, from Proto-Celtic *kel-to, possibly from Proto-Indo-European *kelh₂- (“to strike, beat”). Compare Gaulish theonym *Su-kellos (“good striker”).
Practice speaking and memorizing "Celtae" and many other words and sentences in Latin.