noun, masculine/lɛ.tɔ̃/
letton is masculine in French.
Latvian, the Latvian language
“Certaines reconstructions ont montré que le letton et le lituanien sont les langues encore parlées qui se rapprochent le plus de l'indo-européen.” — Certain reconstructions have shown that Latvian and Lithuanian are the languages still spoken which approach closest to Indo-European.