Where does “doctoor” come from?

doctoor (Middle Dutch) comes from Latin doctor, from Latin -tor, from Proto-Italic -tōr, from Proto-Indo-European -tōr, from Proto-Indo-European -tor-s.

Ancestry of “doctoor”, step by step

StepLanguageWordMeaning
1Latindoctorteacher, instructor; catechist
2Latin-tor-er
3Proto-Italic-tōrForms agent nouns to verb stems
4Proto-Indo-European-tōrDerives agent nouns from verbs, denoting someone...
5Proto-Indo-European-tor-s—
Every word from Proto-Indo-European -tor-s →Every word from Latin -tor →Every word from Latin doctor →