Where does “enter” come from?

enter (Middle English) comes from Anglo-Norman entier, from Latin integrum, from Latin integer, from Proto-Italic *n̥tagros — untouched.

Ancestry of “enter”, step by step

StepLanguageWordMeaning
1Anglo-Normanentierentire; whole
2Latinintegrumnominative neuter singular of integer; accusative...
3Latinintegercomplete, whole, intact; uninjured, sound,...
4Proto-Italic*n̥tagrosuntouched
Every word from Proto-Italic *n̥tagros →Every word from Latin integer →Every word from Latin integrum →