Where does “non-unique” come from?

non-unique (English) comes from English unique, from French unique, from Latin ūnicus, from Latin ūnus, from Old Latin oinos, from Proto-Italic oinos, from Proto-Indo-European óynos — one; single.

Ancestry of “non-unique”, step by step

non-unique traces back through two separate lines of ancestry.

via English unique

StepLanguageWordMeaning
1EnglishuniqueBeing the only one of its kind; unequaled,...
2Frenchuniqueunique; only
3Latinūnicusonly, sole, single
4Latinūnusone, single
5Old Latinoinosone
6Proto-Italicoinoscardinal number 1 Previous: n/a Next: *duō;...
7Proto-Indo-Europeanóynosone; single

via English non

StepLanguageWordMeaning
1EnglishnonObsolete form of none
2Frenchnonno; not; a no, a negative response
3Old Frenchnonno; not; Alternative form of nom
4Latinnōnnot
5Old Latinnoenum—
6Proto-Indo-Europeannénot; no
Every word from Proto-Indo-European óynos →