Where does “nonfocal” come from?

nonfocal (English) comes from English non, from French non, from Old French non, from Latin nōn, from Old Latin noenum, from Proto-Indo-European óynos — one; single.

nonfocal (English): Not focal

Definitions

Not focal

Ancestry of “nonfocal”, step by step

nonfocal traces back through two separate lines of ancestry.

via English non

Step	Language	Word	Meaning
1	English	non	Obsolete form of none
2	French	non	no; not; a no, a negative response
3	Old French	non	no; not; Alternative form of nom
4	Latin	nōn	not
5	Old Latin	noenum	—
6	Proto-Indo-European	óynos	one; single

via English focal

Step	Language	Word	Meaning
1	English	focal	Belonging to, concerning, or located at a focus;...
2	New Latin	focālis	—

Every word from Proto-Indo-European óynos →