Where does “ot-” come from?

ot- (Volapük) comes from German Oktober, from Latin octōber, from Latin octō, from Proto-Italic oktō, from Proto-Indo-European oḱtṓw, from Proto-Indo-European aḱ- — sharp, pointed; sharp, pointed, edgy; sharp,...

Ancestry of “ot-”, step by step

ot- traces back through two separate lines of ancestry.

via German Oktober

StepLanguageWordMeaning
1GermanOktoberOctober
2Latinoctōberof October
3Latinoctōeight; 8
4Proto-Italicoktōeight
5Proto-Indo-Europeanoḱtṓweight
6Proto-Indo-Europeanaḱ-sharp, pointed; sharp, pointed, edgy; sharp,...

via English october

StepLanguageWordMeaning
1EnglishoctoberThe tenth month of the Gregorian calendar, following September and preceding November
Every word from Proto-Indo-European aḱ-Every word from Proto-Indo-European oḱtṓwEvery word from Proto-Italic oktō