Where does “Lețmō” come from?

Lețmō (Livonian) comes from Proto-Celtic let-, from Proto-Celtic letos, from Old Czech léto, from Proto-Slavic lěto, from Proto-Indo-European leh₁tóm.

Ancestry of “Lețmō”, step by step

Lețmō traces back through two separate lines of ancestry.

via Proto-Celtic let-

StepLanguageWordMeaning
1Proto-Celticlet-—
2Proto-Celticletosside
3Old Czechlétosummer
4Proto-Slaviclětosummer; year
5Proto-Indo-Europeanleh₁tóm—

via Livonian mǭ

StepLanguageWordMeaning
1Livonianmǭground
Every word from Proto-Indo-European leh₁tóm →Every word from Proto-Slavic lěto →Every word from Old Czech léto →