Where does “avengeth” come from?

avengeth (English) comes from English avenge, from Middle English avengen, from Old French avengier, from Old French vengier, from Latin vindicō, from Latin vindex, from Latin dīcō, from Latin -tiō — limestone; chalk; the finish line.

avengeth (English): third-person singular simple present indicative...

Definitions

third-person singular simple present indicative...

Ancestry of “avengeth”, step by step

avengeth traces back through two separate lines of ancestry.

via English avenge

Step	Language	Word	Meaning
1	English	avenge	To take vengeance (for); to exact satisfaction for by punishing the injuring party; to vindicate by inflicting pain or evil on a wrongdoer
2	Middle English	avengen	—
3	Old French	avengier	to avenge
4	Old French	vengier	to avenge, to take revenge
5	Latin	vindicō	to lay claim to as one's own (often with sibi)
6	Latin	vindex	claimant, vindicator
7	Latin	dīcō	to say, talk, speak, utter, mention
8	Latin	-tiō	tion, -ation, -ing
9	Latin	dissertātiō	(spoken) dissertation, discourse, disquisition
10	Latin	dissertus	arranged, disposed; explained
11	Latin	disserere	second-person singular future passive indicative...
12	Latin	dis-	asunder, apart, in two; reversal, removal;...
13	Latin	calceus	shoe
14	Latin	calx	limestone; chalk; the finish line

via English eth

Step	Language	Word	Meaning
1	English	eth	A letter introduced into Old English to...

Every word from Latin calx →Every word from Latin -tiō →Every word from Latin dis- →