Where does “wit tooth” come from?

wit tooth (English) comes from English Wit, from English with, from Middle English wiþ, from Old English wiþ, from Old English wiþer, from Proto-West Germanic wiþr, from Proto-Germanic wiþrą, from Proto-Indo-European wī-tero- — apart, asunder; away from, against.

Ancestry of “wit tooth”, step by step

wit tooth traces back through two separate lines of ancestry.

via English Wit

StepLanguageWordMeaning
1EnglishWitSanity
2EnglishwithAgainst; In the company of; alongside, close to;...
3Middle Englishwiþwith
4Old Englishwiþagainst, opposite; along, towards; with
5Old Englishwiþertoward, against; again, against; against, in...
6Proto-West Germanicwiþrtoward, against
7Proto-Germanicwiþrątoward, against
8Proto-Indo-Europeanwī-tero-further apart
9Proto-Indo-Europeanwiapart, asunder; away from, against

via English tooth

StepLanguageWordMeaning
1EnglishtoothA hard, calcareous structure present in the mouth...
2Middle EnglishtothAlternative form of tothe
3Old Englishtōþtooth
4Proto-Germanictanþstooth
5Proto-Indo-Europeanh₃dóntstooth
6Proto-Indo-Europeanh₁ed-to eat
Every word from Proto-Indo-European wiEvery word from Proto-Indo-European wī-tero-Every word from Proto-Germanic wiþrą