Where does “tertius” come from?

tertius (Latin) comes from Latin trēs, from Proto-Italic trēs, from Proto-Indo-European *tréyes.

tertius (Latin): third, the ordinal number after secundus and...

Definitions

  1. third, the ordinal number after secundus and...

Ancestry of “tertius”, step by step

tertius traces back through two separate lines of ancestry.

via Latin trēs

StepLanguageWordMeaning
1Latintrēsthree; 3
2Proto-Italictrēsthree
3Proto-Indo-European*tréyes—

via Proto-Italic *tritios

StepLanguageWordMeaning
1Proto-Italic*tritiosthird

Words derived from “tertius”

Every word from Proto-Indo-European *tréyes →Every word from Proto-Italic trēs →Every word from Latin trēs →