Where does “let-” come from?

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

Ancestry of “let-”, step by step

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

Words derived from “let-”

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