Where does “juro” come from?

juro (Portuguese) comes from Old Portuguese jur, from Latin jūre, from Latin iūs, from Latin dīcō, from Latin -tiō, from Latin dissertātiō, from Latin dissertus, from Latin disserere — small stone, pebble; gravel, rubble.

juro (Portuguese): interest; bonus, reward; usury

Definitions

interest; bonus, reward; usury

Ancestry of “juro”, step by step

Step	Language	Word	Meaning
1	Old Portuguese	jur	—
2	Latin	jūre	—
3	Latin	iūs	law, right
4	Latin	dīcō	to say, talk, speak, utter, mention
5	Latin	-tiō	tion, -ation, -ing
6	Latin	dissertātiō	(spoken) dissertation, discourse, disquisition
7	Latin	dissertus	arranged, disposed; explained
8	Latin	disserere	second-person singular future passive indicative...
9	Latin	dis-	asunder, apart, in two; reversal, removal;...
10	Latin	calceus	shoe
11	Latin	calx	limestone; chalk; the finish line
12	Ancient Greek	χάλιξ	small stone, pebble; gravel, rubble

Every word from Ancient Greek χάλιξ →Every word from Latin -tiō →Every word from Latin dis- →