Where does “oo” come from?

oo (Middle English) comes from Middle English oon, from Old English ān, from Proto-West Germanic ain, from Proto-Germanic ainaz, from Proto-Indo-European óynos — one; single.

oo (Middle English): a, one; Alternative form of O

Definitions

  1. a, one; Alternative form of O

Ancestry of “oo”, step by step

StepLanguageWordMeaning
1Middle Englishoonone; singly, by oneself, by itself
2Old Englishānlonely; entirely alone, solitary, single; one
3Proto-West Germanicainone
4Proto-Germanicainazone; some
5Proto-Indo-Europeanóynosone; single

Words derived from “oo”

Every word from Proto-Indo-European óynos →
oo — Etymology, Origin & Word History | Etymology Explorer