Where does “co-uncle” come from?

co-uncle (English) comes from English co, from English company, from Middle English companye, from Old French compaignie, from Old French compain, from Latin compāniō, from Latin com-, from Latin con- — resin, gum; to say, speak.

co-uncle (English): of a man, an uncle of one's niece or nephew who...

Definitions

of a man, an uncle of one's niece or nephew who...

Ancestry of “co-uncle”, step by step

co-uncle traces back through two separate lines of ancestry.

via English co

Step	Language	Word	Meaning
1	English	co	Clipping of company; they; them
2	English	company	A team; a group of people who work together...
3	Middle English	companye	A company, band, small group, or team of people;...
4	Old French	compaignie	companionship
5	Old French	compain	Alternative form of compaing; friend; companion
6	Latin	compāniō	comrade
7	Latin	com-	allomorph of con-
8	Latin	con-	Used in compounds to indicate a being or bringing...
9	Latin	cum	with, along with; at; -fold
10	Old Latin	com	Alternative form of cum
11	Proto-Italic	kom	with, along, at
12	Proto-Indo-European	ḱóm	beside, near, by, with
13	Proto-Indo-European	ḱe	Deictic particle, here; Post-positional...
14	Middle English	kyt	—
15	German	kitt	putty certain kinds of cement used for fixing e.g. window panes
16	Old High German	kuti	—
17	Proto-West Germanic	kwidu	gum, resin
18	Proto-Germanic	kweduz	resin
19	Proto-Indo-European	gʷet-	resin, gum; to say, speak

via English Uncle

Step	Language	Word	Meaning
1	English	Uncle	radiotelephony clear-code word for the letter U
2	Middle English	uncle	uncle (brother of one's parents)
3	Old French	uncle	Alternative form of oncle
4	Latin	avunculus	maternal uncle, mother's brother; mother's...
5	Proto-Indo-European	h₂éwh₂os	maternal grandfather; maternal uncle

Every word from Proto-Indo-European gʷet- →